Make sure you have good answers to the questions/prompts:
1) Tell us a bit about yourself. Keep this one short and sprinkle it with ways to jumpstart the conversation.
2) Why medicine? If you prepare one question, prepare this one.
3) What would you bring to your medical school class?
4) Name your biggest strength/weakness. For weakness, how have you overcome that weakness?
5) If you're a reapplicant, prepare to explain what you think went wrong and how you remedied it. Be succinct.
6) What is your support system in medical school? How would you cope if you were to attend school far from that support system?
Be prepared to explain how your experiences will help you succeed in medical school. Above all, to thine own self stay true. Don't say things to please the adcoms. Say what feels true to you but within reason and with respect to the job you have to get done, which is to sell your interviewers on lobbying for you with the adcom. Good luck!