Your law school personal statement provides Admissions Committees with the opportunity to evaluate your writing and your ability to communicate in a clear, concise, and effective manner. It is most important that your ideas be well-organized and focused. Your theme choice is not typically limited to "Why do you want to attend law school?" but should be a topic that reflects personal characteristics and strengths, decision-making processes, significant contributions, accomplishments and/or special experiences that are not fully revealed elsewhere in your law school application.
Think of the personal statement as your opportunity to share your positive personality traits in a positive way. This should not be viewed as an opportunity to explain, apologize for, or defend a negative issue or experience, such as a poor academic record or LSAT score. In choosing a topic, consider your personal background, influential experiences, as well as the personal significance of certain events in your life.
Most importantly discuss the "hows" and "whys" of your experiences. Why did you make a particular decision? How did you benefit from the choice you made? What did you value or gain from your experience? Discuss the personal significance of an event.
Keep in mind that the topic is your choice. Law schools will be interested in analyzing the content quality of your essay as well as learning more about you. In fact, since law schools do not usually provide interviews, your personal statement serves as an opportunity for admissions officers to get to know you as an applicant. Sometimes it's helpful to think of the personal statement in this way: If I had ten minutes with an Admissions Committee, what would I want them to know about me that isn't already explored in my law school application?
Try to personalize your statement by avoiding the use of passive expressions. Instead use active language. Perfecting your grammar and spelling is a given. Vary your sentence structure and write engagingly. Many law schools will ask for a personal statement to be two pages, while others will set word limits (i.e., no more than 500 words). As long as the personal statement strongly holds the reader's attention, a slight deviation from the suggested length will not be a problem. Two double-spaced pages with readable font (size 11 should be the smallest you use) and appropriate margins are acceptable by most law schools.