Caravanners and motor homers. What do you use to make your beds more comfy??

[Ledkr]

The kids go in the over cab bed and our seating area converts to a huge double for us but Jeeze I feel as if I'm sleeping on a board! It's soooo hard. Last night we had a memory foam topper and a sleeping bag to lie on and although slightly better, it was still not that great.
I've been looking at SIM what are they like? Or does anyone know where I can get a piece of form cut to size?
Any other tips welcome, thanks.

We use memory foam that has been cut to size in our van. From www.comfortzleisure.co.uk who are fantastic. It is quite thick though so when we need more space in the van we tend to take our SIMs that we used to take camping. Good luck finding something