If you want to pick-up some girls you should know some rules of behavior. You should know what to say and what you shouldn't say.
So here they are:
Do not talk about any of your (family, work, money) problems, if you do it you are more like a friend. You need to be a boy friend or a lover and not a friend. Don't forget to talk more about her life, hobby and stuff like that.
Don't talk about anything negativel. Keep everything positive. You can tell some interesting jokes. (Not vulgar).
Just try to make her laugh. (but not all the time or she will think that you are a clown)
Don't say bad things about your previous girlfriends or ex-wives.
Remember that "all girls are sisters." (Feministic phrase)
So be careful. Focusing on her and her interests and you will do your job.

So that's it. Guys go and pick some girls up!