Know your weapon. I worked in a hunting shop for a few years and was surprised by how little people know about weapons and ammunition. For example, how important it is to zero your rifle when you change ammo.
You need to be a great shot as you owe the animal a clean, quick death. Practise in different environments and simulate stalking by shooting with a beating heart, run or jump a few times then shoot. Learn to know and control your body and breathing.