Disclaimer 1: The information I have on how admissions committees use GRE scores is entirely based on information I received from professors at the universities and departments that I am applying to. This can also be field specific. Please take this information with a grain of salt and inquire at your own prospective programs for more information. Remember that GRE scores are nowhere close to the most important part of your application, and many programs don't use them beyond a cutoff or correlations with GPA.
GRE scores are primarily used, in conjunction with GPA, to weed out the lower end of applicants from the pool. This does not mean that low GRE scores will immediately disqualify you from a program, however. Committees take a holistic view. If you have another outstanding aspect of your application (e.g. letters of recommendation or publications), low GRE scores may not take you out of the running. But if you already have a weak application, low GRE scores may cut you from the pool. Only one school I looked at had a GRE cutoff listed on the website (70th percentile in all sections).
I've heard that the verbal section matters more for humanities and social sciences, and the quantitative section matters more for the natural sciences, but I approached the test believing that both are equally important. I don't subscribe to the idea that social sciences and humanities don't need to be good at math, and that natural sciences don't need to be good at reading/writing. Of course, ask your programs if they weigh each section differently, but I approached this blog post with the idea that all sections are of equal importance.
GRE scores are also used as one of many factors that can qualify you for a competitive departmental fellowship. Nominations are made based on a variety of factors, including GRE, GPA, publications, letters of recommendation, and prior professor contact. Then, nominees are interviewed and final decisions are made. The professors I talked to told me that competitive GRE scores for their specific programs start at 80th percentile in every section, but the average is much closer to 90th percentile. So I set that as my goal when I was studying.
Disclaimer 2: Going into my GRE preparations, I was already relatively good at the verbal, quantitative, and writing sections. My approach to studying was not to learn new material. It was to refresh the material that I had already learned, since GRE math is mostly high-school level, verbal is common of higher reading levels, and writing is in one of the simpler formats. Remember that everyone is coming into GRE preparation with different levels of schooling, different learning styles, and different life circumstances. I'm merely sharing what I did with the circumstances that I had. I think that the study methods I describe below are best suited for those who know the material, but need more practice to get to the higher score ranges. Adjust your own study methods as you see fit.
How I studied for verbal:
I primarily used Magoosh to study. I watched the verbal video tutorials and took notes throughout to make sure that I retained the tips, but I didn't do any practice questions. Most of the tutorials were on how to approach the questions. I found that the hardest part of the verbal was figuring out what the question was asking and identifying the trick answers. Comprehension for the reading passages comes with practice. The only thing I can say that helped with that was being an avid reader of both fiction and academic journals. For vocabulary, I only used the free vocabulary book (see below) from Magoosh. Again, being an avid reader, my vocabulary already included many of the words on the test.
How I studied for quantitative:
Again, I primarily used Magoosh to study. I didn't watch the video tutorials, but I did read through the free equations book (see below). I didn't try to "memorize" these; instead, I tried to understand each one and how they might be used. All of these equations were from high-school level math, but I had forgotten their applications for standardized tests. When I did the practice questions from Magoosh, I used the custom settings to start with only medium-level questions. Once I had finished all of those, I went on to only hard-level questions. Then I went to only very-hard level questions, until I had finished all of the ones that Magoosh offered.
How I studied for analytical writing:
To study for the writing portion, I read through the sample essays on the ETS GRE website, as well as the reviews for each one. I focused on reading through the two essays that scored 6 and 5, breaking each one apart and thinking about the structure of each. Mostly, I focused on figuring out how my essay would be structured, since the GRE prefers a "formula" of sorts. Essentially, if you stick to the 5-paragraph format that you learned in gradeschool, you'll be good. Don't try to be profound or sound smarter than you are. Just stick to the basic format and make sure that your examples all relate to the prompt and that you writing flows clearly.
Other study materials:
I didn't use any study books, like ETS, Princeton, Barrons, or Kaplan. I did use the Manhattan 5lb Book for quantitative, but I got tired of it after one chapter. Magoosh better suited my study needs and was more adaptive to my learning style. If you can afford it, I would recommend getting Magoosh, instead of buying multiple books.
My practice scores:
Powerprep Test 1: V 158 / Q 160
Powerprep Test 2: V 160 / Q 160
Magoosh Predicted Score Range: Q 155-160 (No V)
I'm going to be a hypocrite and say don't freak out on test day. But I did exactly that. Since you can't stop some of the subconscious anxiety that will come up, just do everything that you can to not elevate it. Don't drink coffee right before the test, because you'll get jittery and need to pee every five minutes. Make sure to eat a good breakfast or lunch (I had a subway sandwich and some juice). Don't do anything out of the ordinary, like pull an all-nighter or join a pie-eating contest right before the test. Also, I have heard too many stories about anxiety ending up in lower-than-expected scores on test day. Anxiety can make or break your test, regardless of how much you study. So, try as hard as you can to not let it get the best of you.
When I took the test, the office I went into had four main rooms: the waiting room with lockers, the check-in/security room, and two testing rooms. I left everything, including water, in the lockers in the waiting room before I went to the check-in area. There, I had to have my picture taken, show my I.D., give my signature, turn my pockets out, and get waved down with a metal detector. Then I was taken to a computer that the assistants set up specifically for me. Whenever I wanted to take a break, whether it was scheduled in the test or not, I had to go through the entire procedure again. The actual testing area was pretty nice. I had a padded swivel-chair, so I took off my shoes and sat cross-legged to be comfortable. I was provided with a few sheets of scratch paper and pencils, as well.
In order to get used to the testing format of the computer-based GRE, I highly recommend taking the ETS Powerprep Tests, which are available for free via the ETS GRE website.
The test will begin with the two writing sections: issue and argument. Read more about the format and question types here and here. You are given 30 minutes for each essay, including the time to read the prompt. You cannot use standard shortcuts like ctrl+v; you have to use the buttons at the top of the screen. You also cannot use the "find" function. The hardest part is the the program will not autocorrect your misspelled words, and it will not underline your bad sentence structure. This means that you will need to pay close attention to common mistakes like "teh" instead of "the".
Then you will get either a verbal or quantitative section. You are given 30 minutes to complete 20 questions for each section. The first sections for verbal and quantitative will be "medium" difficulty. Depending on how you do in these first sections, the second section for each, verbal and quantitative, will either be "easy", "medium", or "hard"; this is because the test is adaptive by section. You cannot get a top score without advancing to the "hard" section in the second half. For each of the second sections for verbal and quantitative, you are given 35 minutes to complete 20 questions. Read more about test format here, verbal here, and quantitative here.
Halfway through the test, you will get a 10 minute break to walk around, stretch, go to the restroom, get a snack, etc. You can also take a break at any time throughout your test. I took a 5 minute break after my second essay to stretch and take deep breaths to relax, so don't be afraid to take more time if you need to. Just remember that any unscheduled breaks are eating into your allocated test time for that section.
At some point during your test, you will get a non-graded extra section of either verbal or quantitative. You will not know which section is your non-graded section, so treat all of the questions that you encounter for any section as if they are all graded.
My actual scores:
Verbal 164 (93rd percentile)
Quantitative 164 (89th percentile)
Analytical Writing 5.5 (97th percentile)
These resources are in addition to those already available through the ETS GRE website.
If there is anything that I didn't address here, leave a comment and I'll get back to you as soon as possible.