This has been a bit of a revelation for me... this idea of opening someone before you open your mouth.

The thing is that there are so many different kinds of smiles, and to use your smile in the best way possible you are going to have to practice in front of a mirror and maybe take some pictures of yourself. Learn your different smiles. Don't force them. Imagine something that makes them come naturally. It takes some time, but be patient and practice, find some good thoughts to trigger you, and pretty soon you can flash between different smiles relatively easily and without it seeming forced.

The smile I find the most useful is the "good friend" smile. I think of how it would feel if I were meeting a close friend whom I haven't seen in a long time. That warm, welcoming, "damn it's good you're here" smile. But, it's important not do it with that sparkle of recognition in your eyes. Might have to practice to break that habit. You also hold eye contact longer than usual with this smile. But you don't look them over too much. You know who they are. Good bartenders use this type of smile a lot. It opens people up. It becomes natural to move closer to each other.

Now if they return the smile with something similar, you are golden. It doesn't matter what the fuck you say. Now if they look confused, you may not gotten rid of the recognition in your eyes. Try to replace it with happiness. (I'm almost embarrassed to say it, but I often think of fluffy baby animals when I want to look happy.) Often it's some where in between, and then I base who approaches whom on how positively (make them come to you) or confused (go to them) they respond. Of course, sometimes they'll look away or maybe look at you weird, but that's life. All you did was smile. :) If you practice, you'll never come off like a creeper.

I've field tested this quite a bit in clubs/bars. I find it's often the best option with loud music. Now, of course it's a bit easier for girls to do this than guys, but don't let that stop you!!