Never feel bad about trying and not buying. I spend a pretty decent amount of money on clothes (and I work in retail) and I rarely walk into a place, try things on and leave with them the same visit. I usually plan my koppage over long periods of research. Also sometimes you don't realize how much you really want something until you've tried it on and then left it and realize 'holy fuck i need that in my life'. Most good retailers understand this. Just be friendly and courteous. IE don't try wander in and try on the whole fucking store ten minutes before closing time. other than that really don't worry about it, it's our job to help you find something you like, clean up after you and make everything look pretty. the end.