Not really, but like others I also buy on the small size so that I can try and get as much use out of it as possible. Part of my problem, though, is that I buy almost all my clothes online so I can't try them on in person so I have to make my best guess when it comes to fit/size. Most of the time I manage to get it right but I do have a few items that were too big to start off with that I couldn't send back because it wasn't worth the postage.
I do make one exception. If I can buy a lot of clothes (like on ebay) at once with various sizes some that will fit and some that might be too small, I'll do that with pants but NOT with tops (I wear a 30GG/H so no way am I going to buy a standard top without trying it on first unless it's PJs or something, normally I try to order from places that you can order by your bust size).