Select a place for your proscenium between two trees outside or somewhere inside the house with enough depth and width to accommodate a playing space.
Hammer one large nail into walls on the opposite ends of a room. Knock on the wall and listen for a thud to find the support stud; this is the best place for a nail. Make the nails as level as possible. If you do not want to mark your wall, use two free-standing coatracks or tall lamps. Weigh these down at the base with homemade sandbags or garbage bags filled with dirt.
Tie the end of the a rope to each nail or homemade stand. The amount of rope you'll need will depend on the size of the room, so stretch the rope across the length of the room between the two nails to measure it. Leave about 6 inches at each end to tie the rope to each nail, using an overhand or basic knot to secure the rope. If you are draping a particularly heavy sheet, use a figure-eight knot. Loop the end of the rope around the long portion to the other side, over the top of the loop then through the loop. Pull the knot tight.
Drape two sheets over the rope. Drape them next to each other with an opening in the center; these will act as stage curtains.
Pin the back part of the sheet to the front portion using a safety pin. Pin the sheets together closest to the knot on either end and as close as possible to the rope. Do the same at the center of the sheet, but keep this pin loose. This will allow the performers to open and shut the curtain.
Place folding chairs facing the curtain.