Polyethylene or silk weave underlayer next to my skin for comfort and wicking. Then thin woven merino wool layer, then breathable nylon or poly shirt and pants, then breathable waterproof fleece shell. That is the clothing extreme, for the sleeping bag I've got a 0 degree 4.5 lb poly bag, oversize, in rectangular form, a full size self inflating mattress pad underneath, and a waterproof breathable fleece blanket to wrap around the bag if need be. This all goes inside a 2 1/2 man 3 season tent, with a deluxe poly tarp guyed and poled over the top of that if need be. But all that is luxury. I usually make do with only part of that list.