As you guys probably all know, I'm young and have a very preppy clothing style.
I would get extra-small button ups and polos from the store American Eagle and some small shirts from Abercrombie and Fitch, but they still looked too baggy to be fashionable. (I'm 5'3", 125 lbs lol) So this is for all of you little guys out there.
A&F Kids! Their little boy's section has the same fashionable clothing for
much cheaper. I bought 2 polos and a pair of shorts for $60.00, which would have costs twice as much at the real A&F. Plus, the shirts fit a lot better, creating the illusion that you can fill out a Men's size. I got a large in the Polos, I'm working on getting a few button ups.
I'm not so sure about the jeans, but I got a size 16 in the shorts. Everyone who sees me as a "girl" tells me I have man legs anyway
Back to the shirts. The sleeves come down to a normal length (not passed my elbows like the others) and the shirts are tight, but baggy enough in the chest to allow for some hiding

Anyway, if this is your style, go for it. It's a lot cheaper and looks great. Even if it's not your style, go for the little boy's section in another store. For me personally, the clothing looks a lot better.