An essay? Essays take...spark. Luck.
I wrote my main essay about my addiction to news, in simple conversational tone with a short bit of dialogue near the end. It flowed. It had life and humor and personality -- all those things you can't do by formula. My Yale-specific essay was about my sport, but while writing it I realized why I really loved it -- the other people with me. And so I wrote about them, and my small role in their lives.
If you write an essay and come out knowing more about yourself then when you started, it's probably pretty good.
Why do you like politics?