Dont think... just go up to her!
1) start by introducing yourself (Name etc)
2) Tell her that she cought your eye and that u decided to come talk to her.
By now you should be able to tel if she is interested in you or not by her reations, answers, and body language. So if things are looking up continue to conversation by telling her a little about urself, then asking her a little about HERself.
3) DONT BE SHY! DONT BE SHY! DONT BE SHY! If you are shy, or blush, or stutter, or are insecure, she will see that and thats a big turnoff. ( To avoid having these feelings and being able to control it, go to a shopiing centre, and just start approaching random hot chicks, till eventually u will feel comfortable walking up to a chick and speaking to her.
4) Go to
Sosuave and read everything on that site, that will also help u, and make sure that u read the bible as well. thats a MUST.
With practice, u will be able to approach any girl u want.
Laterz...