Safety,not only for your self, but for others.
Where a Harnesswhen in the tree, falling and getting hurt will really mess up a season.
Make sure you are looking past your target before you shoot. You NEVER should assume that you are alone in the woods. Bullets go a long way. Make sure you know where your hunting buds are hunting. Bad things can happen when you don't check out what is beyond the deer. Could be another person.