Years ago some guy advocated using a surplus parachute as a tipi. His first step was to lay the parachute out flat and doubled, so that you had two half-circles folded together. He claimed that two layers of fabric next to each other acted like a tent and a fly, to prevent condensation. Then he staked the bottom of the chute in a circle, and lifted the peak with a rope thrown over a tree branch. I never tried his system, but who knows? It might have worked.