I guess it really depends if you're just looking for one nights or more long-term relationship. I can't really help with the former, I've never really been that kind of guy. But for the latter, I'd say this: just be yourself. It sounds cheesy, but at the end of the day, it's what works best. If you just are yourself you'll automatically feel more confident end secure as you won't always be trying to act a part. Of course, self-confidence, independence, good appearance, good manners, dolphins, etc. will all help you. But don't try to be someone you're not. It may work short term, I guess, but sooner or later, if the relationship draws out, you will get tired of it, your nature will bleed out and the girl will wonder who she really is with. I won't work long.
Also, and it might be the most ironic piece of advice, I've personally had the most luck when I stopped looking and trying. Easier said than done, I know, but... Yeah. I'd suggest to just do your stuff, be yourself, be generally gentle and sociable, and without even really realizing it you'll encounter someone and things'll happen naturally.