Approaching women huh, wow that's an easy concept. When it comes to approaching desirable women, I'm the farking king of kings, the pros of pros, the pros of hoes, as you will. It's not difficult in anyway to approach women, but it is somewhat difficult to get them to sleep with you, but let's take baby steps first.
First off don't worry too much if she likes you or not, just go into it with the intention of having fun. DON'T let her have any power over you, and why would you, since you DON'T even know the girl. But, that can be changed easily. The perfect way to approach a woman is to simply say...HELLO, or better yet HI.
I'm serious fark all that how are you sh1t, that the other pick up artists be spitting at you, because YOU DON'T KNOW her, so why would you care how she is, she isn't worth that much to you. So for a pua opener just say HI, and let the chips fall where they may.