Usually sweats or yoga pants, with a cami. Prana's Amaya and Kari are my favorite camis ever: thick straps, flattering cut -- I wear them instead of a bra most days.
For pants, I have a few Vic Secret pairs, some whateverbrands from thrift, and I also have cotton jersey pajama bottoms from Target that are super comfortable for workouts. They have shorts, too.
And since it's cold in my old house, I wear my favorite crazy "elf" cardigan from the fabu etsy artist
Katwise. I have her leg-warmers and arm-warmers, too. Everything's one of a kind. This is my
cardigan. I have even done yoga while shopping at Katwise's "parades." Down dog, page refresh, forward bend, page refresh. It's crazy. But it got me my cardigan!