Step #1: Get to Know Her
Unless you're a Robert Pattinson or a Zac Efron (in case of looks, of course), the chances are quite less, that a girl will go to the prom with a complete stranger. So, you need to get acquainted, and introduce the girl to some of your brighter aspects. If you get to know her, you could be funny or intelligent, or probably sing a song if that's your talent.