I wear a small back pack and a fanny pack. The small pack I think is needed to not mess with your shooting. Too much weight in a pack can cause problems over the course of a long day. On my fanny pack is a bow hook. This is a great tool for glassing so you don't have to put your bow on the ground. The other thing is most of the stuff in my pack is cloth[game bags and clothing, those types of things]. My Fanny pack is loaded with things I need out quickly, so I don't have to remove my pack. Things happen very fast bow hunting, so not having to fool with your pack is a good thing.
Gselkhunter