Please use your voice and not your mother's, your father's, your guidance counselor's nor your coach's! The essay has to sound like you! This is the most important tip to a successful essay! The second tip is to "show and tell": start with an anecdote and base the rest of the essay on that. Why? You need to keep the essay interesting. So, 1) show your voice and 2) keep it interesting!
Check out this link which talks precisely about this: