You can lasso some game(deer, elk, etc.) and kill it with the knife. Keeps pelts from becoming damaged
Also, I heard on the youtube that if you manage to lose a legendary pelt, it still goes to the trapper. You just lose the ability to sell it. Can still get special gear for it.
Use eagle eye to spot gators and fish underwater, and deadeye to bowfish or use a firearm.
Bring a temporary horse from camp along with your main horse. This allows you to carry more pelts.
Once you have the legend of the east satchel, you can hunt herds of buffalo to stock up on food. They're on the open plains, and they're slow. If you kill about 10 at a time, usually 1 or 2 will attract vultures and rot.
Dynamite arrows work great for legendary animals.