Look for universities that offer graduate programs leading to a PhD in the academic major of interest. Ask professors and career counselors for a list of schools that meet your criteria.
Check admissions requirements in current graduate catalogs of each prospective school. Make sure you have the minimum number of academic requisite classes in your chosen field. If you haven't, plan to spend more preparatory time to get the background you need. (Reference 1)
Take the GRE, or Graduate Record Exam, and any additional subject tests, if applicable. Testing requirements for physics and math PhDs are different from tests needed for liberal arts PhDs.
Fill out application materials. Prepare a statement of purpose that identifies your special interests in your field and the type of research you wish to pursue, whether applied or theoretical. Order official transcripts from all schools you have attended.
Sign up and take classes, tutorials and seminars until your requirements are fulfilled. Take ancillary course work that benefits your degree plan, where applicable.
Synthesize the materials and knowledge you have accumulated over the years to formulate a topic of focus for your book-length dissertation. Develop a dissertation proposal, or prospectus, that describes a central theme, process or theory that you plan to fully explore through your research.
Ask three professors to sit on your dissertation committee. Select professors familiar with your work through your academic contact.
Write your dissertation. Follow guidelines particular to your program and your field of study. Use the required citation and text formatting specified by the graduate school.
Consult with your dissertation committee for approval of a final draft of your dissertation.
Defend your dissertation at an oral defense. Meet face to face with your dissertation committee and potentially other experts, to address questions they pose. Be prepared to meet any challenge of your research and writings.
Make any final revisions to your text from feedback. Minor corrections usually don't require further committee review. Get the final version reviewed to conform to the requisite manual style. Hire a professional to make sure the text is perfect before getting your bound copies. (Reference 2)
Comply with electronic submission requirements, such as those used at the University of Texas at Austin. (Reference 3)
Graduate with your PhD diploma. Do a final checklist through your graduate school office, or the registrar, to be sure that all requirements have been met to qualify you for the PhD diploma. Pay any library, parking and other fines that may bar access to your graduation.