This really is the easiest shelter you can build. The idea is to literally pile as much stuff on as possible to help weatherproof and insulate the shelter. It is intentionally left small so you can maximize the effects of body heat by not heating a large area. If you have a little bit of cord, tie three longs of stick together, two short that you can get in under and one long pole to run the length of your body and some; stack on the ribbing, and then go to town with insulating materials. Pine boughs work great. There are several picture because they each illustrate a different way of framing up the opening on the same shelter. as a side note, its worth throwing a little dry material under your sleeping bag as a great insulator.