The best and easiest mounting method I've found is a simple spring loaded clip. Mine came with a bunch of generic GoPro mounts that I bought as a group on ****. (By the way, I would recommend the generic mounts, as mine have proven to be more durable, and probably 75% less expensive that the authentic ones.)
I use my spring loaded clip for almost everything. I hook it on my belt and carry it everywhere, then when I want to get some footage, I can clip it somewhere and point it toward the action. I've clipped it on my bow quiver, my belt (facing my target), my shoulder, and the forearm sleeve of my bow arm.
I also clip it to my lifejacket when on the water, backpack straps, tree limbs, etc. It's been by far the best mount for my use.
Here's an image of what I'm talking about:
https://goo.gl/images/mquq6u I don't mount my GoPro on the bow because it does shake a lot when releasing an arrow.