Out in the woods I never carry a tent. I prefer an improvised shelter, almost always a lean-to. When alone I use a military poncho, which is plenty big enough for myself and my gear. When travelling in a group of 2 or 3 we bring a tarp, about 6'x10'. If necessary (in cold or very windy weather) I also construct some extra side screens, as simple as a few sticks and a big plastic bag.