So i'm kind of a nut for clothes. and there's a lot of hot girls working in clothing stores. this is obviously the easiest place to start a conversation with girls as i often ask them for advice on what to buy, and they often ask questions and such aswell. in fact it's one of the few times i feel very little anxiety when talking to chicks.

so the question is, how do you move from very light conversation, which is easy to create in this sort of situation, to actually trying to get a number? there's a certain level of insincerity due to the fact that they're trying to make sale obviously, so it's hard to know if a girl's actually interested in you at all, or finds you repulsive lol, despite the fact that you may have been talking to them for a few minutes and getting a load of compliments.

anybody found success in this kind of environment?

Those kind of girls called "Hired Guns".
you need to play a different game with them and that's because they are hired to talk to you, be nice to you, smile to you and make story short - give you IOI's.
It's part of their job.

I'm not so good at "Hired Guns".. so I recommend that you read MM, he explains very well how to pick up a "Hired Gun".

cheers