morawel

I see this was answered above but wanted to add that this does depend on your field and the programs you’re applying to. Lots of programs in natural sciences, ecology, fisheries and wildlife, etc. will require you to have been in contact with potential advisors and even have faculty sponsorship before applying, in some cases. In these fields, it’s helpful to reach out to faculty you’re interested in working with to inquire if they have funding and are accepting students for the upcoming year. Sometimes funded positions are even advertised and you will apply and interview directly with the professor before the formal application process. Disregard if this isn’t relevant to you, but this is a general biology forum so I wanted to put it out there! 

You might find some helpful insight in this thread: 
 

Oh my goodness, you should not be paying research expenses and travel costs. I’m sorry if that’s not a helpful response but you should know that it’s not normal or expected! I’m curious how your program works; did you apply to work with a specific PI? And if so, did they develop the project with you, and was there any discussion of funding? This is why many programs will not accept students without at least partial guarantee of funding (e.g., a grant your PI has that you will be working under), but I don’t know how it works in your field. Do you have a dissertation committee, and did you go through a research proposal process? I cannot imagine allowing a student to take on an international research project with no funding. At the very least, your advisor and department should be helping you find grants to apply for. 
Unfortunately I think it’s pretty standard to have to pay student fees even when your tuition is covered, as much as that sucks. But the research expenses are a different story. I hope you are able to find some support. 

Oh my goodness, you should not be paying research expenses and travel costs. I’m sorry if that’s not a helpful response but you should know that it’s not normal or expected! I’m curious how your program works; did you apply to work with a specific PI? And if so, did they develop the project with you, and was there any discussion of funding? This is why many programs will not accept students without at least partial guarantee of funding (e.g., a grant your PI has that you will be working under), but I don’t know how it works in your field. Do you have a dissertation committee, and did you go through a research proposal process? I cannot imagine allowing a student to take on an international research project with no funding. At the very least, your advisor and department should be helping you find grants to apply for. 
Unfortunately I think it’s pretty standard to have to pay student fees even when your tuition is covered, as much as that sucks. But the research expenses are a different story. I hope you are able to find some support. 

Oh my goodness, you should not be paying research expenses and travel costs. I’m sorry if that’s not a helpful response but you should know that it’s not normal or expected! I’m curious how your program works; did you apply to work with a specific PI? And if so, did they develop the project with you, and was there any discussion of funding? This is why many programs will not accept students without at least partial guarantee of funding (e.g., a grant your PI has that you will be working under), but I don’t know how it works in your field. Do you have a dissertation committee, and did you go through a research proposal process? I cannot imagine allowing a student to take on an international research project with no funding. At the very least, your advisor and department should be helping you find grants to apply for. 
Unfortunately I think it’s pretty standard to have to pay student fees even when your tuition is covered, as much as that sucks. But the research expenses are a different story. I hope you are able to find some support. 

You might find some helpful insight in this thread: 
 

I recently got an iPad for this purpose and I really like it so far. I briefly considered the Surface models but decided they were too expensive and I already have a pretty good laptop, too. But they did seem nice! I went with the basic 9.7” iPad with the iPencil, which is great for highlighting and marking up papers. 

I recently got an iPad and I love it! I chose the basic 9.7-inch model (not the Pro) and also got the Apple Pencil. For reading papers, I've been using the Mendeley app since it's what I already use as a reference manager, and it syncs all the info and PDFs to my account. You can highlight and add notes directly in the app. I've played around with other reading apps a little bit, and the built-in Books app is actually pretty good. I haven't done much note-taking yet, but I do like OneNote app for writing lists and things, since it also syncs across devices with your Microsoft account. The Apple Pencil is great once you get used to it, and hand drag won't be a problem.

I also have to disagree with NicholasCage's comment.  90-95 percent of academic institutions in the United States are teaching-focused institutions; therefore, most of us will end up there.  Your teaching skills are going to be an important part of the hiring process at those places.  Plus, even research-intensive institutions would rather have a professor who can connect well with students AND is a great researcher than a professor who is a terrible teacher (unless that second research has mad money).

My advice:

1. Don't spend an inordinate amount of hours preparing...well, anything for class.  Learn to limit your prep time.  Part of that is because the students are going to ignore a lot of it anyway, but most of it is because you need to learn balance early in your career.  For example, I have a tendency to do line edits on students' papers, so I try to limit myself to editing only the first page to a page and a half and then add a comment like "You have errors like this throughout your paper; please proofread and fix."

2. Related to #1, learn to wing it.  I create slides for my lectures but I no longer write extensive notes.  I actually find I lecture better when I don't have notes, because then I'm more free-form.  And I don't just mean talking extemporaneously - I mean switching gears when your students look bored or aren't getting it.  As you get more experience this will become easier.  

3. Create an organizational system for grading.  Buy folders or binders or trays or whatever you want to organize 1) graded papers 2) to-be-graded papers for different classes.  This way you won't have paper all over the apartment, which drove me absolutely nuts.  You also will be better able to keep up with assignments, lowering the risk of losing one.  If you have a choice, absolutely collect everything electronically through the course management system.  Forget all that paper.

4. Totally agree with not assuming that upper-level students know how to write properly.  If you are at an elite university, do not assume that your students are automatically good at whatever it is you're teaching them.  I was kind of shocked my first semester TAing at the quality of work I got from students at my elite university - I went to a not-elite place and assumed that the students at the elite place would be simply amazing, since the students at my not-elite place were great.  And they are amazing...in different ways...in the typical way that college students are amazing in their ingenuity and creativity (both for good and evil).  But they're not substantially smarter or better than students from other, less elite institutions. They're just richer and better prepared (on average).

A few years ago my younger sister asked me to help her with a paper that was very similar to a paper I was currently grading for a class very similar to the one she was taking at her regional public college, to which she commuted from home.  My family is blue-collar; she went to a regular public high school and was a slightly above-average student.  Her paper was better written than MOST of the students' papers in my class.

5. If you are TAing for a professor and it gets down to 2 weeks before the class starts and you haven't heard from them, contact them yourself.  Most times you will get an apologetic "Oh yeah, I'm teaching a class!"  If you get a brush-off equivalent to "Mmm, I'll think about it in two weeks," prepare for an interesting semester.

I think the most important to remember is similar to what hashslinger said.  Remember that we were the nerds in high school and college - we showed up shiny and excited to learn.  Particularly if you are teaching an intro class, your students will not be as excited as you, and some of them will never get excited.  They may be taking it because it's an easy GE requirement, or they need some extra credits, or they heard it was an easy A.  Perhaps 10% of your class will decide to major in the field; maybe another 10-20% will not but will be genuinely interested.  The rest will be some varying levels of "whatever." Visualize that 20-30% when you are preparing lectures, but realize that not even close to everyone is in that area and some people will be grubbing for grades.

Oh, also, don't be afraid to indulge in geekery, as long as you don't go down the rabbit hole too deeply.  One of the things that has reached my students is how geeked and enthusiastic I am about my interest area.  Even when they think I'm silly and uncool, they still appreciate my passion, and in some of them it has led to really productive curiosity.
 
ALSO.  I lurk on the "In the Classroom" threads on Chronicle of Higher Education's forum.  There are lots of experienced professors there and they have AWESOME advice (and really funny stories).

I beg to differ on this one. There are certainly some questions that you can't ask to some people but that doesn't mean they shouldn't be asked. They just need to be asked discreetly to the right person. Typically, these are the sort of things that you should ask grad students in a casual environment removed from professors, such as:
-Which professors shouldn't be put on committees together?
-Is the stipend enough to live on/what do students do to support themselves beyond the stipend?
-What is Professor X's reputations as an advisor?
-How prepared to students feel on the job market? How successful have recent grads been?
-Are their factions/cliques among the grad students? Among the professors?
-How many students leave the program before completion? Why do they leave?
-How flexible rigid are the course/program requirements? 
-Where do faculty and students butt heads?
 
I could go on, but that should give you an idea of the sort of things you really do want to know and should do your best to find out on a visit. Some of these you could ask to professors, but seeing as they're trying to convince you to attend, grad students are the better ones to ask. They too might be trying to sell the program but they were in your shoes more recently and thus are more apt to be more candid about their experience. Plus professors can be pretty oblivious about some of these things. You should definitely broach these topics tactfully, but they are by no means off limits.
 

Many conferences have travel awards you can apply for, or lower registration rates for early career researchers and students (you could probably still consider yourself a student). Some conferences also have tradeoffs where you can volunteer for a few hours and get a fee waiver, or a shared hotel room, or something. Good luck!

This was my experience for my master's degree, and it worked out well for me. I don't have much to add because I think you've summarized the pros and cons well. I found that my advisor was eager, ambitious, invested in us, and had a good appreciation for what it's like to be a grad student these days. (I particularly appreciated this last one. It could be really difficult to have an advisor who is out of touch with things like the current job market in your field or how things have been changing for students, financially and otherwise.) On the other hand, it may have helped to have an advisor with a more established network, especially when moving on to finding jobs and/or PhD positions.
I've been given the advice that finding a supportive advisor whom you get along with is the most important factor in choosing a program. I'm not sure that the prestige of the program where your advisor did their PhD is that important. If it means that their background is particularly strong in areas that you're interested in, or that they've worked with people you may be interested in working with in the future, then that's definitely a bonus, but you should look for those things regardless of the prestige of their degree.
It's possible that professors could leave the department at any point, but yeah, it makes sense to think about this if there's a possibility that they may not receive tenure. I've been told that it's okay to actually ask professors whether they plan to stay at their current university long-term (or at least long enough to advise a student through a master's or PhD.) Obviously this isn't always planned (especially the tenure situation), but it might be nice to know if they are considering looking for jobs elsewhere. However, I haven't actually been brave enough to ask this of any potential advisors  
One thing I would suggest is to make an effort to connect with students in other labs. Even if your advisor is bringing on other new students at the same time, you won't have the benefit of being around students who have experience in the department and can help you navigate the program. Your advisor may actually not even know the answers to some of your questions about things like classes, paperwork, requirements, tuition and fees, etc. So definitely make an effort to establish a support system of other graduate students!

About your dog: I think that depends entirely on you and your program. I am in a social science program where the majority of my analysis and writing can be done from home, and I prefer to work from home or from a library (as opposed to my cube in the windowless cube farm). When I was taking classes I was generally there from 9-6 or so, but now that my coursework is finished I am rarely at the school itself. I go for meetings, seminars, interesting kinds of things and I do most of my work remotely. My time is verrry flexible, and if my building didn't prohibit it I would get a dog in a heartbeat. Another thing to keep in mind: a dog can be a great comfort when you're all stressed out over graduate school.

Advice?

Age:
-Don't feel like you have nothing to offer just because you are younger. I was 22 when I started graduate school. You got accepted to the program for a reason, and chances are you are just as equipped as any older students are to successfully complete the program, just in a different way.

-Your older classmates may be just as terrified as you. Talk to them. You have a lot in common. You are, after all, in the same place.

-You will feel like an imposter, like you don't belong, or like you are constantly behind. Or all three. It's normal. It will pass. (Well, sort of.) People of all ages go through this.

Adviser related:
-If you are lucky enough to get both research interest fit and personality fit perfect, congratulations! But sometimes, personality fit is more important than research interest fit as long as the research isn't too different. A great adviser is interested in your career development, likes you as a person, advocates for you, and wants to hear your ideas. Even if his or her research is quite different from yours, they may give you the autonomy to work on your own projects and just supervise you. A bad personality fit will drive you nuts, even if you love his or her research. Consider that when evaluating your adviser fit. (This will vary by field: research fit may be less important in the humanities, more important in the natural and physical sciences. Social sciences are somewhere in-between.)

-Don't be afraid to be straight up blunt with your adviser when it comes to asking about your progress. Ask if you are where you should be both academic program wise and getting-a-job-after-this-mess-wise.

-Be proactive. Advisers love when you draw up an agenda for your one-on-one meetings, come with talking points and progress to share, have concrete questions to ask, and have overall shown that you have been thoughtful and taken control of your own program. Of course, this won't immediately come easily to you, but in time you will work up to it. Every semester I type up my semester goals, and at the beginning of the year I type up annual goals. I show them to my adviser and we talk about whether they are too ambitious, or whether I need to revise them, and how I can meet them.

-Don't expect your adviser to actually know what courses you have to take to graduate. They will know about comprehensive exams and the dissertation, but a lot of professors don't really keep up with the course requirements, especially if their program is in flux. Get you a student handbook, and find out what you need to take. Map it out in a grid, and check off things when you finish them. Show this to your adviser every semester. You may have to explain how such and such class fills a requirement.

-Nobody loves you as much as you, except your mother. Keep this in mind as you take in advice from all sources, including your adviser. Your adviser is there to guide you, but that doesn't mean you have to do everything he says.

Studying:
-You will have to read more than you ever did before, in less time than you ever have before, and you will be expected to retain more than you ever have before. The way that you studied in undergrad may need some tweaking. Be prepared for this.

-Corollary: you may find that your methods change with age or interests or time. I preferred to study alone in college, but in grad school, I prefer to study in groups. It keeps me on task and the socialization keeps me motivated. You may find that you shift from being a more auditory learner to a visual learner or whatever.

-You will feel behind at first. This is normal.

-At some point you will realize that your professors don't actually expect you to read everything they assign you. This, of course, will vary by program, but there will be at least one class where the reading is actually impossible to do in one week. The point is to read enough that you know the major themes and can talk intelligently about them, and then pick some of the readings to really dig into and think more deeply about.

-For most programs, don't worry so much about grades. If you stay on top of your work and do what you're supposed to, you will probably get an A. How much grades matter varies from program to program. In some programs, a B is a signal that you are not up to par, and more than a few Bs will warrant a discussion with your adviser or the DGS. My program isn't like that - A, B, it's all meaningless. My adviser doesn't even know what my grades are. But at almost all programs, a C means you need to retake the course, and two Cs means you have to convince the DGS not to kick you out.

Extracurricular activity: What's that? No, seriously:
-A lot of your time will be unstructured. You will have coursework, but most grad classes meet once a week for two hours and you may have three classes. You may have meetings with your adviser every so often and some seminars or things to catch (like we have grand rounds and colloquia that are required), but a lot of time will be unstructured. However, since you have so much more work than you had in undergrad, you actually will have less free time than you had in undergrad. This may initially cause you great anxiety. It did for me. Some people love unstructured time, though. (I don't.)

-Because of this, you'll have to be planful about your non-grad school related stuff.

-TAKE TIME OFF. DO it. It's important for your mental health. However you do it doesn't matter. Some people work it like a 9-5 job. Some people take a day off per week (me) and maybe a few hours spread across the week. Some people work half days 7 days a week. However you do it, there needs to be a time when you say "f this, I'm going to the movies."

-Find your happy place, something that keeps you the you you were when you came in. I love working out. It gives me energy and I feel good. I stay healthy. I also love reading fiction, so sometimes I just curl up with a good book, work be damned. You have to give yourself permission to not think about work, at least for a couple of hours a week. You may also discover new hobbies! (I never worked out before I came to graduate school.)

-Your work will creep into all aspects of your life, if you let it. This is why I hate unstructured time. You will feel guilty for not doing something, because in graduate school, there is ALWAYS something you can do. ALWAYS. But since there will always be more work, there's no harm in putting it aside for tomorrow, as long as you don't have a deadline.

-You may need to reach outside of your cohort for a social life. None of my close friends are in my doctoral cohort. I've met master's students in my program, master's students in other programs, and I know a few non-graduate students I hang out with, too. Go to graduate student mixers. (If your university doesn't have any, organize some, if you like planning parties.) Join a student group that doesn't take up too much time. I had a doctoral acquaintance who kinda laughed at me because I joined some student groups other than the doctoral student one, and I was usually the only doctoral student in those groups, but I met some close friends (and future job contacts) and had a good time.

-DO NOT FEEL GUILTY FOR WANTING A LIFE OUTSIDE OF GRADUATE SCHOOL. This is paramount. This is important. You are a well-rounded, complex, multifaceted human being. NEVER feel bad for this. Everybody wants some kind of life outside of work. Yes, you may loooove your field, but that doesn't mean you want to do it all day long. Some other doctoral students, and perhaps professors, may make you feel bad about this. Don't let them. Just smile and nod. Then disappear when you need to.

Career:
-This is job preparation. Remember that from Day One. Always be looking for ways to enhance your skills. Read job ads and find out what's hot in your field, what's necessary, what's in demand. For example, in my field statistics and methods are a hot commodity, and they're not a passing fad. I happen to really like statistics and methods, so I have pursued that as a concentration of mine.

-Don't be afraid to take on volunteer work and part-time gigs that will give you skills that will be useful both inside academia and out, as long as it's not against your contract. Your adviser may be against it, but he doesn't have to know as long as it doesn't interfere with your work.

-If you want to work outside of academia - if you are even *considering* the possibility - please please definitely do the above. Even if you aren't considering it, consider the possibility that you won't get a tenure-track job out the box and that you may need to support yourself doing something else for a while. You will have to prove to employers that you have developed usable, useful skills and this is one of the easiest ways to do it. But don't overdo it - get the degree done.

-For more academic related ones - always look for opportunities to present and publish. Presentations look good on your CV. Publications look better. When you write seminar papers, wonder if you can publish them with some revision. Write your seminar papers on what you maybe think you may want to do your dissertation on. Even if you look at them three years later and think "these suck," you can at least glean some useful references and pieces from them. Discuss publication with your adviser early and often, and if you have the time and desire, seek out publication options with other professors and researchers. But if you commit to a project, COMMIT. You don't want to leave a bad impression.

-If you can afford it, occasionally go to conferences even if you aren't presenting. You can network, and you can hear some interesting talks, and you may think about new directions for your own research. You can also meet people who may tell you about jobs, money, opportunities, etc.

-Always try to get someone else to pay for conference travel before you come out of pocket. Including your adviser. Do not be shy about asking if he or she can pay. If he can't, he'll just say no. Usually the department has a travel fund for students, but often it's only if you are presenting.

-If you are interested in academia, you should get some teaching experience. There are two traditional ways to do this: TAing a course, and teaching as a sole instructor. If you can help it, I wouldn't recommend doing a sole instructor position until you are finished with coursework. Teaching takes a LOT of time to do right. You should definitely TA at least one course, and probably a few different ones. But don't overdo it, if you can help it, because again, it takes a LOT of time. More than you expect at the outset. If you are in the humanities, I think sole instructor positions are very important for nabbing jobs so when you are in the exam/ABD phase, you may want to try at least one. If your own university has none, look at adjuncting for nearby colleges, including community colleges. (I would wager that the majority of natural science/physical science students, and most social science students, have never sole taught a class before they get an assistant professor job. At least, it's not that common n my field, which straddles the social and natural sciences.)

-Always look for money. Money is awesome. If you can fund yourself you can do what you want, within reason. Your university will be thrilled, your adviser will be happy, and you can put it on your CV. It's win-win-win! Don't put yourself out of the running before anyone else has a chance to. Apply even if you think you won't get it or the odds are against you (they always are), as long as you are eligible. Apply often. Apply even if it's only $500. (That's conference travel!) Money begets money. The more awards you get, the more awards you will get. They will get bigger over time. If you are in the sciences and social sciences, you should get practice writing at least one grant. You don't have to write the whole thing, but at least get in on the process so that you can see how it's done. Grant-writing is very valuable both in and outside of graduate school.

-Revise your CV every so often. Then look and decide what you want to add to it. Then go get that thing, so you can add it.

-The career office at big universities is often not just for undergrads. I was surprised to learn that my career center offers help on CV organization and the academic job search, as well as alternative/non-academic career searches for doctoral students. In fact, there are two people whose sole purpose it is to help PhD students find nonacademic careers, and they both have PhDs. This will vary by university - some universities will have very little for grad students. Find out before you write the office off.

-It's never too early to go to seminars/workshops like "the academic job search inside and out", "creating the perfect CV," "getting the job," etc. NEVER. Often the leader will share tips that are more aimed towards early graduate students, or tidbits that are kind of too late for more advanced students to take care of. This will also help you keep a pulse on what's hot in your field. It'll help you know what lines you need to add to your CV. And they're interesting.

Other:

-Decide ahead of time what you are NOT willing to sacrifice on the altar of academia. Then stick to it.
I'm serious. If you decide that you do NOT want to sacrifice your relationship, don't. If it's your geographical mobility, don't. I mean, be realistic, and realize that there will always be trade-offs. But you have to think about what's important to you for your quality of life, and realize that there is always more to you than graduate school.

-If you don't want to be a professor, do not feel guilty about this. At all. Zero. However, you will have to do things differently than most doctoral students. Your adviser will probably never have worked outside of the academy (although this may vary depending on the field) so he may or may not be able to help you. But you have a special mission to seek out the kinds of experiences that will help you find a non-academic job. Test the waters with your adviser before you tell him this. My adviser was quite amenable to it, but that's because I told him that my goal was to still do research and policy work in my field just not at a university, AND because it's quite common in my field for doctoral students to do non-academic work. If you're in a field where it's not common (or where your professors refuse to believe it's common, or it's not supposed to be common)…well, you may be a little more on your own.

-Every so often, you will need to reflect on the reasons you came to graduate school. Sometimes, just sit and think quietly. Why are you doing this to yourself? Do you love your field? Do you need this degree to do what you want to do? Usually the answer is yes and yes, and usually you'll keep on trucking. But sometimes when the chips are down you will need to reevaluate why you put yourself through this in the first place.

-To my great dismay, depression is quite common in doctoral students. Graduate work can be isolating and stressful. Luckily your health insurance usually includes counseling sessions. TAKE THEM if you need them. Do not be ashamed. You may be surprised with who else is getting them. (I found out that everyone in my cohort, including me, was getting mental health counseling at a certain point.) Exercise can help, as can taking that mental health day once a week and just chilling. Don't be surprised if you get the blues…

-…but be self-aware and able to recognize when the depression is clouding your ability to function. Doctoral programs have a 50% attrition rate, and this is rarely because that 50% is less intelligent than, less motivated than, less driven than, or less ambitious than the other 50% that stays. Often they realize that they are ridiculously unhappy in the field, or that they don't need the degree anymore, or that they'd rather focus on other things in life, or their interests have changed. All of this is okay!

-You will, at some point, be like "eff this, I'm leaving." I think almost every doctoral student has thought about dropping out and just kicking this all to the curb. You need to listen to yourself, and find out whether it is idle thought (nothing to worry about, very normal) or whether you are truly unhappy to the point that you need to leave. Counseling can help you figure this out.

-Don't be afraid to take a semester or a year off if you need to. That's what leaves of absence are for.

Lastly, and positively…

…graduate school is great! Seriously, when else will you ever have the time to study what you want for hours on end, talk to just as interested others about it, and live in an intellectual community of scholars and intellectuals? And occasionally wake up at 11 am and go to the bank at 2 pm? Sometimes you will want to pull out all of your hair but most of the time, you will feel fulfilled and wonderfully encouraged and edified. So enjoy this time!

Many conferences have travel awards you can apply for, or lower registration rates for early career researchers and students (you could probably still consider yourself a student). Some conferences also have tradeoffs where you can volunteer for a few hours and get a fee waiver, or a shared hotel room, or something. Good luck!

I worked for several years on programs that supported low-income graduate students (and prospective graduate students), and you could say my role included 'wardrobe mentoring.' Regardless of where you live, if you wear a size 0-14 women's (XS-XL, 28-40 waist men's), you can probably find a thrift store where you can outfit yourself for interviews for $20-$30. If you wear a bigger or smaller size, it could be a bit more challenging at this budget, but it's still worthwhile to hit the thrift store first, and certain parts of your outfit can be found there either way. If you feel truly at a loss for where to start, I would say aim for something like the following.
[NOTE:  these suggestions are admittedly very gendered and conservative, and I am highly conscious of the fact that they provide nothing in the way of helping people to display their unique personal style, etc. Surely there are many individuals to whom these suggestions also do not well apply, probably including many students in the arts, as well as those who privilege ethnic/cultural expression in their dress, etc. Furthermore, I do not wish to reinforce the idea that there is (or should be) one way of dressing in academia. I strongly feel the opposite is true. But, alas, I also wish to help make accessible an "academic outfit" to those with limited resources, or to those who have a limited awareness of what is expected of them in this department in most disciplines. Finally, the stores I suggest below are purely motivated by awareness of budget, availability, and supply of clothing consistent with the status quo in academia. They are not my faves, and they might not be those that are most responsible with respect to clothing manufacturing, etc.]
These suggestions pertain to most non-professional masters and doctoral students doing routine visits to (or interviews with) graduate schools, etc., who wish to play it safe in their dress. For dress in professional school environments (law, business, medicine, etc.), as well as in the arts and other fields that might have different standards, I would ask a trusted mentor in the discipline for advice.
FOR WOMEN
PANTS/SKIRT/DRESS
Dark (black, navy, grey, etc.) pants or simple skirt (hits at mid-knee or just below, nothing shorter, and longer will be hard to pull off for most body types), or shift dress. Skirt can be pencil-style to just slightly flowing. Avoid skirts with excessive material that could look cutesy or like you're headed to the swing dance. In general, pants should go to (and not beyond) your shoes and should not be too "skinny." If you're aiming for safe, avoid overly trendy styles or prints for the purposes of interviews and visits. 
TOP/BLOUSE
If wearing a dress, skip this. If not: Light, solid (or very subtle pattern) neutral colored (white, light grey, light blue, etc) blouse. If you don't mind tucking-in, an ironed button-up collar shirt always looks great. I can't stand tucking and always feel it causes muffin top on me (eek!), so if you're like me, find a top that fits you well and feels comfortable and does not hit much below or above the hip bone. Do not show belly, and do not wear a long shirt that resembles a nightshirt. Your shirt should also not be frayed or wrinkled at the hem, if you're wearing it outside your pants/skirt. I like to wear a comfy, slightly flowing tank-top. It should reveal ZERO cleavage, even if you lean forward slightly, and it should not fit very tight at the chest or elsewhere. If your buttons are pulling, get another shirt, or use double-sided fabric tape to keep your shirt closed. Of course, too big and your clothes can look messy, so try to get something that fits somewhat closely but that reveals minimal contours (including belly rolls or pants/skirt cut-in). Reasonable fit is key to both neat appearance and comfort. Better if your clothes are just slightly on the spacious side than that they are slightly tight (other way around, of course, when you head to the clubs later that night). 
CARDIGAN/BLAZER
Cardigan sweater and/or structured jacket ("blazer") in either a solid, neutral color or a simple pattern. There are plenty of good choices for color/pattern combinations. I'm just trying to provide simple go-to pieces that will help you move through the thrift shop (or other shop) efficiently. 
SHOES
Simple flats, or low heal pumps, in black or other neutral color. No sparkles or excessive buckles, etc, or large flashy brand names pasted across shoes. If in a cold place, simple boots (if possible). Cheap black rain boots will work if you're from somewhere warm and don't have appropriate winter boots. You won't likely be walking outside for too long. Avoid giant, clompy, fur-everywhere boots that look like novelty slippers.
COAT: A trench coat or wool (style) button-down coat, if headed somewhere cold or rainy. Also, an umbrella for rainy places (particularly if you fear for your hair). 
SOCKS/TIGHTS: No "fun" or bright socks or tights. Lightweight, non-bulging socks, knee-highs, or tights in a neutral (probably dark) color. If wearing flats, fine to go without socks, but not in a snowy or cold place. In general, wear skirts or dresses with tights or nylons (very hot places, like Miami and Hawaii, could be exceptions if high temperature is 75+). Black matte is often best option for tights. 
SCARF: If you settle on the simplest option in each of the above categories, you might consider adding a lightweight, thin scarf around your neck, for a bit of flare, or to cover up unflattering imperfections in the fit of your shirt or sweater/jacket, or just for fun. Still, choose a simple pattern, that has at most one vibrant color. Also, the scarf should not crowd your face or cause a distraction. Look around the web for ways to tie your thin scarf. 
HAIR: For most other than Black women, in general, your hair should be kept tidy and simple, whether you wear it up or down. For Black women, your hair tends to look incredibly stylish no matter what; still, if you're not feeling it on interview day, pull it back, or wear it in a scarf, or in the fashion that is most comfortable for you. Ethnic women, in general, will enjoy more flexibility when it comes to hairstyle and accessories. A White woman in a head band or scarf might appear overly casual. It's typically less the case for non-white women. People have a tendency to fiddle with their hair when they wear it in new ways, so be sure you are comfortable and practiced with your hairdo. Likewise, wear your interview clothes around town (avoiding ketchup, etc.) in advance, so you can work out the kinks before interview day. 
JEWELRY: Simple, sparse jewelry, if any. Fitbit-type watches are ok, but best if without flashy wrist bands. 
MAKE-UP: Simple, daytime make-up, if any. 
HATS?: No hats, unless religious 
MULTIPLE DAY VISIT: you can wear the basics of your outfit for more than one day. Include two different shirts and/or change-up your scarf and hairdo for a totally different look on a second day. On a third day, change either sweater or blazer (to one of a different color) for a completely fresh look. 
SHOPS: shops to look for clothing (in the US): Any thrift shop, and especially the big ones (Goodwill, Savers, Value Village, St. Vincent's, etc.). Also, check the clearance areas of stores such as Ross, Old Navy, Kohls, Target, JC Penny, Sears, and even Forever 21, H&M, etc.
FOR MEN
Read over suggestions for the women. Your outfit will be nearly the same (pants, button-up shirt, cardigan and/or blazer, plus overcoat in cold places), with the exception that their scarf will be your neck tie. No, you don't need a neck tie, and in many places you might be the only one wearing one, but if your outfit is very simple, you might like to have one for a bit of flare). No joke-style or flashy neck-ties. No white socks. Shoes should be simple, probably black or brown, comfortable enough to walk a bit. If you're at a loss, I would suggest Oxford style, tie-up shoes. You can get these in all sizes and widths online (Amazon, etc.), and Walmart also usually carries some low-priced "dress" shoe options in various widths. For guarantee of fit and quality (if you have hard-to-fit-feet and/or a more flexible budget), go to a store that specializes in extended sizing options. You will not be sorry. No moccasins, and skinny little loafers can look like bedroom slippers (particularly to your 60 year old POI). Your hair should be freshly tidied (whether you wear it short or long), and your face groomed (whether you have a beard or not). 
Anyone is welcomed to PM me for more, including help identifying styles to fit your particular body type or aesthetic (I am sorry I provide little help here in terms of finding larger sized clothing beyond thrift stores) and good resources within your specific town.
Best of luck to all!