One of the vital skills I taught myself how to do during A-levels was how to roll a coin across the back off my knuckles. Doing this with a 'tactical drop' so that it bounces in front of them (normally waiting at a bar) I've found is a good way of getting a girls attention without even saying anything. The vast majority of the time they're impressed and generally amazed.

However, I've yet to work out what the best next thing is to do from there though, whether to make an attempt at a C&F remark about magical fingers, or go for challenging them to try which leads to what i've now realised is some light kino.