At my work our dress code includes blouses for women, and I have been using compression tank tops to smooth out my figure. However I've been meaning to start using my shoulder posture support corrector while at work as well, however the straps are very uncomfortable without an under shirt (with sleeves).
These compression short sleeve t-shirts seem perfect! They compress just enough that it smooths out my figure, and they are long enough that it seems they won't become un-tucked even if I have to bend over - I'm so excited to start using them. I ordered my regular size and they fit snugly. If you want something that has very minimal compression (but still get the smooth effect), I'd suggest just ordering 1 size up.