The personal statement for the majority of medical school application asks the applicant essentially why he or she wants to become a doctor. The majority of applicants answer this question with some variation of "I want to help people." While many of these applicants are answering honestly, they need to realize that the admissions panel will be receiving hundreds and thousands of such answers. Thus, if you truly do want to help people, state it in your essay very specifically. Outline community service or volunteer work that you've done or charities abroad for whom you've worked or donated time. Outline specific goals in the realm of "helping people" that a medical degree will help you complete.
While many will tell you that your personal statement for medical school should be interesting, few will tell you exactly how to make it interesting. Often, writing an interesting essay comes from writing honestly. Before you write your personal statement, make a list of life events that you've experienced that have impacted your life and how. Then choose the one that is the most interesting and that most strongly connects to why you'd like to become a doctor. Use that anecdote in your opening paragraph or second paragraph.
Give as many details as possible when you are either explaining why you want to become a doctor or relaying the anecdote about an event that impacted your life. Details make stories more vivid and paint a crisper picture for the reader of your personal statement. They also make your stories and opinions far more engaging, while helping the admissions panel to see you more as a human being and an individual rather than another nameless applicant who would like a spot in their program.