I used one of those "boomerang" pillows from back in the day - you know the ones that are either a V shape or a U shape. I can't afford to buy a new one, and it seems to go OK. I sleep on my side with it between my legs and sometimes under my belly or I roll over more and rest my knee on it, so I am sort of laying on my tummy (I'm a tummy sleeper - Oh! how I miss it!). I do get a sore lower back from time to time, so I put a normal pillow behind me too to support my back when I'm on my side.

I hope this makes sense!

I used to work at TRU and at Christmas time, they can be totally hopeless!