I'll bite. Ask to buy them a drink- guaranteed talking time. Drop your pitch and just try to keep it light and easy. If they aren't talking much, move on after a while- you got better girls to look out for. If you've got a good conversation going, you're either 1. some nice random person or 2. a person they are attracted to, judge this yourself. From this point either bail, or keep talking. From there its really up to you, if its a club, ask them to dance, if its a regular bar, connect with them, drop some digits and move away after a certain time. In the bar situation, come back before you leave and either ask them if they want another drink, or take them to another bar. Don't be too pushy, and after a drink and talking to them for a bit, let them come back to you.