Rigging a tarp as an emergency shelter doesn't have to be a cumbersome affair. Learn a few simple knots like the Taut-Line Hitch, Bowline, and Trucker's Hitch, and you can rig a tarp as a simple A-frame, a lean-to, or any other configuration that makes sense for your circumstances. If you use a tent pole in the center to keep rain from pooling, be sure to soften the contact point with a rag or sock to avoid punctures. Standard tarp sizes such as 5x7 and 8x10 feet will also serve as a ground cloth for most 2- to 4-man family tents. Remember, you are not looking for light weight and efficiency here. A utility tarp is all about economy and versatility.