Imbro - The ones that give you the evil eye are the most fun, because you have absolutely NO chance at all (nothing to lose). The trick is no matter what she says, be extra extra nice to her. If they really hate you, it is very frustrating to them. They want to hate you, but you are so nice. If she says something mean, just laugh it off, and then pour on the charm super thick. Keep a big grin! As you walk out of the store, mumble to yourself "yeah, she wants me". (Like any lie, if you repeat it enough times, people will start to believe it.)
There is this girl in the video store near my house that hated me from go. I have been super nice to her and chatted her up. Now when I come in, I see her sigh. I have broken her will. She wants to hate me but just can't. If she was good lookin', I would have done her by now. I only talk her up for the practice.
Think about a used car dealer selling an old repainted taxi cab. He knows the car has 230,000 miles on it, and lets the sucker think it is 130,000. He talks about it like it just came off of the showroom floor. You sell yourself to women, by telling them how great THEY are (even if it ain't exactly true). A good salesman can sell a $1 bill for $5, because a sale has nothing to do with the merchandise.