Because I wasn't sure which size would work best for me, I ordered both a medium and a large with the intent to return whichever one wasn't the right size. A medium fit me well. I didn't even try the large on. I'm 5'10", normally US size 10, 32" inseam, with nonexistent calves, thicker thighs, and wide hips. It made my almost nonexistent butt look curvy!

These don't retain a lot of warmth from what I can tell. In fact, they may even be chillier than tights because of the material (over 90% polyester and some elastine). That's okay for me because I wanted the shine, and they are shiny!