I just used my regular beg. Sit and swing legs over. I had the bilateral knee done 3/21/19. I was led to believe I could sleep without a pillow between my legs by week 4 or so but it took me months to get rid of doggone pillow. I can’t sleep on my left side, because of vertigo and back, more snoring, but I alternated between back and right side with thin pillow between my legs to allow me to cross one leg over the other which is how I normally sleep. On back I propped pillow under my left shoulder so I leaned towards right. I was most comfortable during day in deep club chair with an ottoman so my legs were straight out. I have a recliner but with that I got more radiculopathy burning in my feet and legs (radiating from my not so good back) but that is almost completely gone now. Each 4 weeks I saw a big change in my overall progress. By 8 weeks I was driving my Prius. Could probably have managed sooner but that was my first post op visit so I waited. Expect to be fatigued in the early months. Listen to it and rest a lot. I still do standing four way leg exercises. Squats, toe raises, side lifts, quads, hamstrings...just 5 to 10 minutes at a time but good to keep that going, plus push down extensions sitting between two chairs. I had full flexion and extension within a few weeks. Have maintained it and now without pushing or trying my legs go past 130 degrees although doc said don’t try for more, since the new knee prosthetics will allow it but it puts stress on the joint. Best to you!!