Clothing

For clothing, consider a thick sweater and wind shell or rain shell instead of a large, bulky parka. Warmth depends only on insulation thickness and a wind/waterproof outer layer. The sweater and shell will be lighter (usually), pack more compactly, and be cheaper (usually). The sweater will also make good pillow stuffing. A down parka or sweater is great, but see the cautions about down sleeping bags. Cotton sweatshirts are very cold when damp, so avoid them if you can. Ponchos are ok as raingear if you don't have to move around, and it's not windy. A rainsuit will keep you much drier if you're hiking or it's blowing.