I know it's about pads (and of course now cots--and luxury hotels), but here's another goodie I like a lot: a
sleeping bag liner. This one is the brand I have, but probably not the exact model--I don't think mine's a mummy-style. They come in cotton or silk, but mine is a fabric like nylon, or some kind of microfiber. Stretchy, very long--it's thin enough to not hinder your breathing if you have it up over your face or your whole head, which is very nice if you have a mosquito or something in your tent, or if you want to get a few more winks after the sun comes up--it blocks a lot of light. And it's stretchy enough that you really don't feel restricted at all by it inside the bag.
But the point of it is it gives you about 10 degrees of extra comfort--makes a 30o bag into a 20o one, etc. And it stuffs into its little bag to about the size of a softball. If you get to a motel and wonder about how clean or critter-free the room is, it's also nice to put it between you and
them.
Nice addition to my camping setup.