I have severe insomnia. I don't sleep at night anymore and basically take very short nap during the day. I have tried everything from meds to self help. Such a battle.
Anyhow I sleep on my back. Before I slept on my side or stomach. Sometimes I do know I lean a certain way where I get sore in other areas. I try to be mindful because I know relying on other areas because of the rsd areas can cause issues too.
Sheets and blankets make a difference too. I have tried multiple matresses and foam toppers. When I was at the pain clinic they suggested a special pillow but I have not got that.
I also have the tv on and a fan. I have tried other things too from quiet room,music,etc. I used to wear ear plugs but now with possible rsd in my ear I can't
I think we are all different in what works and a lot is trial and error and may change along the way.