ORIGINAL: kevin1
As little as possible .
This is the right answer. Every year, I look at what I take to the stand with an eye to eliminating some items. Usually if I can't carry it in a pocket, I won't carry it. The exception is water, snacks, camo mesh for my climber, and my range finder. I carry that in a small backpack which is good for putting clothes into as the day warms up and I strip clothing off. I am usually prepared to hunt from sun up to sun down.