Write a statement of purpose

This should describe what you have already done in your field and what you hope to accomplish with your doctoral research. Good letters will describe who you hope to work with as your research supervisor and the reasons you want to work with that person. Your research program should be in an area that has not been previously researched, or has been underrepresented in the literature.
If youre planning on applying to lots of schools, it can be a timesaver to write a form version of your letter, allowing space to customize the letter for more specific programs. Its very important to tailor each statement of purpose to the particular program to which youre applying. This demonstrates your seriousness and interest in the school. Each letter should read as if youre only interested in studying at that school.