In conceptualizing a theme, you have to consider the main question, "What would you like to say with your essay?" For example, do you want the admissions committee to understand your choice of major and career in relation to your family background, or do you want to share your passion for your chosen field and your desire to achieve excellence in it? Whichever theme you come up with, this has to be unique to you as an applicant and should be related to your personal background, choice of major, and choice of career. The more unique a theme is, the more interesting the essay will be. In this sense, you can capitalize on personal facts you believe are noteworthy of exposition.
6. REVISE, REVISE, REVISE. Have another person (several persons) critique your work. Use fellow students, trusted professors, your parents or significant other _ anyone who will read your statement closely and give you constructive advice. You, yourself, should read your statement out loud; the ear will hear errors (sentence fragments, grammatical missteps) the eye misses. Be aware of unconscious mistakes, like starting every sentence with the work "I", using cliches (example: saying you want to be a doctor to "help people"), or over_stating or exaggerating accomplishments or emotions. Once satisfied, put the statement down, do not over_write it and drain it of all intensity and enthusiasm. Lastly, think on this. Your personal statement is your opportunity to tell your "story" and a window into your humanity _ ultimately, that is what makes it engaging and memorable to the schools you are applying to.