Choose the faculty members of your doctoral committee carefully before writing your dissertation. If possible, work with faculty members whom you trust will keep in regular contact with you throughout the writing process. Faculty members who are willing to work with you and support your academic endeavors are more likely to help you adequately prepare for a successful defense.
Ask your faculty committee to informally pre-approve your dissertation before your scheduled defense. A supportive committee will guide a student to correct any glaring mistakes or other elements in the dissertation that would prevent the defense from being accepted. This doesn't guarantee that your defense will be accepted, but it will reduce the chances of defense rejection.
Confirm your eligibility for graduation. Make sure departmental requirements are completed and all necessary paperwork is filed with your school. Many schools require this to be done before the defense is scheduled, but it is a good idea to double-check that all needed materials have been submitted.
Practice your defense presentation in front of peers who will give can give you helpful feedback on your public speaking skills and clarity of the information you are providing. This can ease the pressure of standing before your faculty committee on the day of the defense, helping you feel more confident and prepared.
Present your defense in sections that coincide with your written dissertation. For example, draw statements and figures from each section and present them to your committee consecutively. Remember that a doctoral defense is a presentation of the research you have conducted, rather than a plea for graduation. Start by explaining the introduction to your study. Continue with background information, research methods, analysis and finish with the outcome.
Create a visual aide. Having a Powerpoint presentation or slide show will not only exemplify your preparedness for the defense, it will help committee members follow along with your presentation. More importantly, offering a visual aide removes the presenter as the focal point for the audience. This can ease your nerves and help keep you on track throughout your presentation.
Prepare for questions your committee will ask you after your presentation. Such questions may include limitations to your present research, and directions for future research. Assume that you will be asked questions for which you have no answer. "I don't know," is an acceptable response to questions that do not pertain to the research you conducted or the surrounding topics.