Is it OK to chat up girls when they're working? Watch
Got into the shop. Say you have a date coming up, ask her to help pick out some clothes. Get to know what sort of clothes she likes on a guy. Then when you're at the counter, you ask her out on a date. Although you will probably have to explain that you didn't really have a date coming up and that the only reason you went in the shop was to get to know her and her tastes little bit.
Go on date.... with the clothes she picked out.
Back to her place, have the sexums.
Probability states that you will only have to get rejected every 50 times before it works. And if that doesn't work just go for the desperate's (you know, your fat birds, your low self-esteem birds and your Scouse birds)