I can't use a backpack since I have to carry my stand in on my back every hunt, and I've found that a fanny pack doesn't quite work either.
I use a shoulder bag marketed for waterfowl hunting. I don't know the brand, but it works good. I just wish it was made of the softer fleecy stuff that some of the newer packs are made of. It's louder than my standplwowing through branches.