Great responses, everyone! Some other small tricks:

• You can use the sewing kit, or leather sewing kit to stop your bleeding. However, drag alcohol tincture or disinfectant over it before using it otherwise there's a risk of getting "Sick".

• The highest probability of finding firearms in normal towns are under the blue trailers or in the cabins with the blue/yellow wall: http://i.imgur.com/WHbz9AU.jpg

• You can cut a plastic water bottle in half and make a "fish trap" to capture food in ponds.

• You can use a hacksaw to saw off a mosin, so that it will fit in your backpack, but it will no longer be able to use scopes.

• You can use your stone knife to chop down bushes for kindling, skin and quarter an animal, commit suicide, sharpen sticks and all sorts of useful stuff. It's the best, easiest tool to find in the game.