1. Take note of her body language. Is she leaning towards you, playing with her hair, reaching out to touch you gently on the arm? Watch out! She probably has lice, and now so does your arm!
2. Make sure she's aware that you can show her the world; shining, shimmering, splendid. Invite her to tell you - and throw in some extra charm here by calling her "princess" - now when did she last let her heart decide? Note: make sure you have access to a magic carpet and a monkey sidekick.
3. Only fart if you're certain it's going to sound hilarious. Or if you've trained your butt to ask for her hand in marriage.
4a) Try not to mention your ex-girlfriends. Unless you dated the actress who played Alex Mack. We'll feel so bad about ourselves comparative to that mystery dream girl that we'll immediately put out. Or we'll get intimidated and leave, rethink it, call you in the middle of the night outside your house and then immediately put out. Like, I'm talking in-your-building's-stairwell immediately.