How to Survive in the Woods
Caves can be great [shelter], but be sure the cave is not already occupied by bears, large cats, snakes or other unfriendly animals; they know caves are good too, and they've been looking for good shelter for longer than you have. Also make sure it's not going to collapse on you- this reduces your chances of survival considerably.
Bear dens are excellent shelters as they provide protection from the elements, but many times you'll find that a bear will not welcome you into its home; unless it is eating you.
Shoe/Boot laces make good rope in an emergency situation, but remember once they're removed, walking will become more difficult.
Chewing leather is bad advice for most modern, chemical-tanned leathers, (great way to poison yourself with chromium and other toxic chemicals)! Besides, do you really want to trade your only real foot protection for a couple of calories? Protect your shoes so you can take a hike to look for nutrition!