We learned this in survival training when I was in the Navy. The Dakota fire hole - conserves wood while minimizing smoke and light from the fire. it also helps cut the light and smoke that can be seen by others or, eh hem, Walkers.
Determine remaining daylight on your hand. Use this simple trick to measure the remaining daylight without a watch. Count the finger widths between the sun and the horizon. Each finger is equivalent to 15 minutes, with each hand totaling an hour.