I sleep mostly on my stomach, although that’s a bit hard and uncomfortable to do with breasts, lol. I’ll sometimes toss to my left or right if I feel like it. I sleep very well despite tossing around.
Mostly on my back...but I move around a bunch due to a handful of pains that pop up every once in a while. Sometimes my back or shoulders hurt...or my knees, or my hips. I just sleep however feels right. On any given night, I probably sleep on my back, stomach, and both sides. I just do what I need to.