How do you prepare for the medical school interview?

The most important thing is really to practice and practice even more! Practice with literally anyone - your parents, teachers, friends, neighbours and even yourself in from of a mirror. A good book that I used was the "medical school interview questions" ISC medical. They give examples of very common interview questions and ideas for what you could say. I went through the book and practiced answering all of the question over a few weekends. Also try and have a structure to your answers. I started with an introduction, middle and a summary for every question. This meant that I gave a brief answer to the question in the first sentence, expanded on this with evidence from my personal statement and work experience etc, and then in one last sentenced, summarised everything that I had just said. That makes your answer much easier to follow and more interesting to listen to.