Let's say I'm in a club and I see a very attractive girl. Logic suggests that if a girl if a girl is visibly hot, she must be hit on all the time, especially at clubs and similar venues. This means that while she might not necessarily be "fed up" with all the more or less skilful attempts at picking her up, she probably has some sort of defense mechanism set up and she doesn't treat her suitors seriously.

In such a situation, what are some good ways of "differentiating" oneself, meaning proving to a girl that you're not just any random douchebag who saw a hot girl at a club and decided to walk up to her? What are some good ways of showing that you're "different"?