Hi, can I buy you a drink?

It's customary to pick up chicks in a nightclub by offering to buy her a drink. If they haven't finished their current drink, you should wait until it's completely finished before dumping the one you just bought into their glass. If you do not receive the attention you want from the drink recipient, be sure to request that they give the drink back so you can pass the unconsumed portion on to the next most attractive person at the bar.