This is a little bit more of a scam, but depending on your personality and the setting, this might work wonders. Stand a few feet away from a girl and look at her hair a bit funny. Secretly have a very small piece of some sort of food hidden between your first finger and thumb. Get caught looking a little puzzled and say, "Excuse me, you have something in your hair." She will certainly be a little self conscious and worry where and what it is. Immediately say, "Let me get that." Reach forward and move your fingers into her hair being careful not to use your thumb or first finger. Pull your hands away and drop whatever you had in your fingers. You could add a bit of sarcasm afterwards and say, "You own me a drink. I don't clean people for nothing."
From: Rich (not me)
From: Rich (not me)