One of the more popular college admissions essay topics asks you to describe a person who has had a significant influence on your life, and then to describe that influence. The word "describe" in the question can lead applicants down a dangerous slope, for the best essays will do much more than "describe"; a winning essay will include a lot of analysis of the way that the person has changed your life.
Whether you are writing about a teacher, coach, parent or celebrity, an essay on an influential person should be as much about you as the person you have chosen. The essay needs to show your character, your self-awareness and your passions. The admissions officers really aren't that interested in hearing about how great your hero is unless you are revealing yourself in the process. Remember, the school is thinking about admitting you, not the influential person in your essay.
For more advice, read these 6 Tips for a College Admissions Essay on a Person Who Has Influenced You.