I'm currently searching for something to wear underneath this thin and rather form fitting dress. Every piece of underwear(Spanx Full slip, Fleexees, etc) I've tried on hasn't done a very good job of smoothing everything out, I'm beginning to wonder if it has something to do with the sizing. Everything seems like its too big in places or not strong enough to smooth out the hips/stomach area. My frame is alright petite, so I'm not looking for something to make me thinner looking, just eliminate some unslightly bulges. Anyone got any suggestions?