How do you find a faculty sponsor for PhD?

[UndeclaredStudies]

Hello,

So I recently completed a master's in sustainability-related topic and would like to continue on to a PhD. However, I am very confused as to how to go about gaining faculty sponsorship. I have gotten some good feedback from email outreach, but most of the responses just tell me that the programs do not have enough funding to take in new students. I am just wondering though how the students in these PhD students got their sponsorship. Is it really just a matter of who you know? Or if your college advisor knew the right people? I have found it quite difficult to get my foot in the door and was wondering if folks here might be able to share how they managed to get into their respective PhD programs. I am just wondering how to politely, yet directly, ask if they would consider taking me. But then I have to see things from their perspective of course. Why would they take me if they don't know me? 

How might I even respond to an email about the program only taking 1 or 2 new PhD students? 

Thank you all!

[strugglebus2k17]

First off, it depends on the field you want to go into and the school you choose. Each school has different programs they employ to sort their students into sponsored research labs. I'm interested in virology/immunology so I choose to look into medical schools that have PhD training programs for this. For my program, the first year we have up to 5 rotations, each 2 months, in different labs that we may be interested in. At the end of the year, if you click with the mentor, they'll take you into their lab where you can begin to work toward your thesis research for the next 4ish years. My program also put together faculty seminars where we would listen to 4 faculty presentations each week to help us decide what we were interested in/if we wanted to rotate in that lab. 

This type of rotation model is pretty consistent among medical school based PhD programs, at least the one's that I interviewed at and were considering. I know in other sciences you have to match with a faculty as a prerequisite for admissions into the school/program. I'm not in one of these types of programs but my best guess/advice would be to email the program director or department chair of the school your interested in if any faculty at the school are looking/has funding to recruit graduate students into their lab for research. 

Most PhD programs, will have the PI fund your PhD education. Only some rare exceptions, like Mayo Clinic, will the Graduate School foot the bill for your training the entire time you are there.