An application sent late reflects badly on you. Ph.D. programs rarely accept late submissions, so have all of your documentation ready and submit your application early. If your application is in before the first deadline, you may be considered for fellowships.
Casting a wide net provides you the greatest chance of acceptance. Though you may have a specific school in mind, realistically every program has more applicants than spots available. Avoid putting all of your hopes on one school.
Letters from faculty are preferred, because they have experience with you on an academic level. Approach only professors who you know will give you a positive letter of recommendation and in whose courses you received high grades. Give the professors copies of your statement of purpose, personal statement and resume, so they can tailor their letter to you and the school to which you are applying. Provide your professors with letter of recommendation forms and addresses, and inform them of the deadlines to ensure your materials are not late.
Your grade point average (GPA) is an important factor in your Ph.D. application. Generally, a GPA of 3.5 represents the admission floor, but some programs set this minimum higher. Grades from courses in your Ph.D. field of study will be of greatest interest to those evaluating your application.
Gaining research experience during your undergraduate studies is very important. It shows the evaluators that you are familiar with research at a professional level and it gives them specific research with which to evaluate your work.
Your statement of purpose can make or break you. A high-quality statement of purpose has three components. The first gives an overview of your research interests. The second summarizes your qualifications, including research experience. Be specific about your role in the research and the outcomes. Note if you were given the opportunity to present the findings to a panel or at a conference, or if the research was published in a journal. In the third component, you detail why you are pursuing a Ph.D. and what topics you hope to research. It is recommended that you name faculty members with whom you would like to work.
A personal statement gives the evaluators a chance to know who you are and where you have come from. If you are a first-generation student, that can inspire evaluators; if you've supported yourself financially, that suggests a strong work ethic. If you were a mentor or tutor or took on other leadership roles, discuss them. Evaluators look favorable on evidence of leadership.