To make a shelter from 3 items
Make a fast emergency lean-to shelter
1. Tarpaulin or Plastic Sheeting or Large Leaf Garbage bags (all of these items are on the list above and should be rolled tightly and packed in the Bug-out bag)
2. Twine or light rope, shoelaces work in a jam
Find a tree branch or rock overhang that is tall enough to reach and has a flat open area on the ground below.
To Make the Shelter
Using the twine, tie 2 of the corners of the opened flat tarpaulin or plastic sheet to the tree branch or use a heavy rock to tie to and set on the rock overhang then use rope or twine to secure the rock in place.
Long poles cut of tree saplings also placed against the rock wall will work. The poles can be put in the ground to make a lean too if the ground is soft enough.
Stretch the tarp out and to the ground for a sloped roof lean-to shelter. Use stick stakes or heavy rocks to hold in place.
Make as secure as possible with extra twine, rocks or stakes.
Lay another tarp, plastic sheet or garbage bags on the ground for a protective waterproof barrier.
Make the underside into your camp.
Face the doorway or open side away from prevailing winds and storms; usually they come from the west. South facing to the east is a good choice for most parts of the USA.