I'm no expert but I have a pretty good success rate of extras at SCs. My standard MO is to dress decent, don't be a slob. Buy the VIP band when you come in. Ask about it and talk to the girl at the front counter. This lets her know you're an ok guy, you have cash, and you're here to have fun. She'll tell her friends.
Find a seat, order a drink/open one if its BYOB. Within a song or two go tip someone. Anyone. But preferably a hot dancer. You're there to have fun, and you have to spend money to have fun. When dancers walk by make eye contact and don't look away. Don't be a creep but don't be a pussy either. Everyone knows why you're here.
When a dancer sits down to talk, talk to her. Be nice. Be friendly and playful. But be upfront about what you want.
I only like the dirty girls, is that you? Of course she will say yes. But it gets the conversation going. How fun/dirty are you? What can I expect from you? Ask if she likes to play.
During the first dance make it clear you expect more. If she doesn't respond, don't do a second dance. Move on and start again. That's part of the fun. When you find a dancer you like that plays, you should be having fun by the 3rd dance max. Afterwards get her number so you can either hook up OTC or you know if she's working when you want to hit the club next.

I've never seen the point of long conversations, back rubs, etc. She's there to make money not friends. Help her do that.

Happy hunting mongers...