If you feel uncomfortable in any of these positions in the dressing room, pass on the outfit. You can be sure you'll be tugging at it all day in the real world.
Okay, so you thought you had a killer outfit when you tried it on in the dressing room. Then you got to school and had the most awkward day ever! Here's a test to make sure you can keep the 3 B's (boobs, butt, belly) in check BEFORE you fork over the cash.