In my tent I like a mil. surplus cot with a foam pad on top so my butt don't get cold.
The foam is held in place by a "single" size fitted sheet (fits a mil surplus cot) and the sleeping bag on top of course.

"Camping places fix themselves in your mind as if you had spent long periods of your life in them.
You will remember a curve of your wagon track in the grass of the plain like the features of a friend."
Isak Dinesen