Past experiences with babysitting, references, if you have any, what your goals are (why you want the job), and some of your hobbies wouldn't hurt. Like, if you are involved in any clubs at school, that sounds good to a parent. Also mention any first aid skills you may have, like CPR.
I'm a parent, and if I were going to hire a babysitter I'd want to know she was kind, reliable, had common sense, wasn't going to invite her boyfriend to come visit her at my house, wasn't going to be under the influence of anything, and wasn't going to steal anything.
You're good with kids, and have never considered eating them.
You're always late, you hate the sound of crying kids, you love pot almost as much as your tatooed boyfriend.