Make a simple small bench

If you use paper, I suggest drawing a floor plan of the stool on cardboard, then cutting it out and folding it. Strong, too.

If you use foam board, it is best to gently burn a small bench with fire, because it is easy to drop "snowflakes" when the foam board is scratched with a knife.

If you use wooden boards, I suggest you nail them to the legs and back of the stool, or use 502 glue.