"My application process began with completing my GRE a year before I graduated. Despite not being the only factor that graduate schools consider, a good score on the GRE can really make the difference between you and other applicants. Many applicants will have a publication or two under their belts and excellent class grades. So what separates you from other applicants? It's not awards or volunteer work, it's the GRE score. This may seem unfair to many but the GRE score is definitely a factor for many schools and departments. After you have your score it's time reach out to labs you are interested in. I suggest applying to no more than 10 schools as registration fees are expensive and the time commitment for each application is significant. Contact labs and PIs that you are interesting in working in and for not just ones that seem prestigious. PIs will know right away if you're heart isn't in the research. After you've been accepted to a number of programs, the school will invite you out to visit the school, the faculty, and the students. It is imperative to ask the students what THEY think of your potential lab and the PI. Also, let the faculty, including your possible future PI, where you have applied. This will give them time to make the offer to you to join the department more competitive. Liking the school is also very important. If you are doing a Ph.D, you may spent 4-6 years of your life there, so you will have to have a connection with the place, not just the research. Work/life balance is paramount. After you've soaked in each program, make sure to think long about where you want to go as you may have multiple choices. Make a pros and cons list and pick the program or school that has the highest pro:con ratio. Since you are a scientist, make a science out of it!"