I go to school and I am very particular about not wearing anything that shows off too much, since I don't want to encourage another guy who is crushing on me... (yes I know it is true, I am not being self obsessed <3)
I don't have much to work with, but I try my best with matching undergarments :] any other ideas?
The guys who are crushing on you are probably looking even how you dress now, as it would take A LOT for a girl to dress a way that's unattractive,especially to guys that like them. Are there things you feel you look best in that you won't wear because of these crushing guys? Do you feel like you loook best in what you're wearing now? Forget about detracting those guys, where what YOU think you look impressive in, & the guy will be just as impressed...
I don't see how what you wear will "impress" him more or less - unless you want him to be impressed with your taste in clothing. In that case, you have to figure it out yourself - you know better than we do what is appropriate, what your limits are, what your tastes are, and I don't think 'we' could help you with any of those things..