Wow, what a can of worms....can someone build a "smiley" for that?
I am glad though that you specified "hunting bag", because they are (should be) as different as night from day from a shooting bag. When you go on a woodswalk, you need all kinds of manure and enough shooting materials for 12 to 25 (or even 50) shots on a woodswalk. When you go into the woods, you need like, 5. If you need more than that to feel comfortable, you've not spent enough time at the range.
Also, your bag and gear should be QUIET, not sounding like a junk truck tromping through the woods like you do on a woods walk. Do the military "hop" test. Hop up and down, and anything that rattles, find it and secure it.
Okay, straight up tips:
Bag doesn't need to be big, in fact, smaller the better. Use soft material, because stuff rattles and rools around in bags made of hard "tooling" leather, a lesson hard learned in the woods. tie your powder measure to the strap but be sure that it is long enough to reach into the bag so that it isn't swinging around and getting caught on brush and inevitably getting LOST. Believe me on this one, I've left plenty of stuff in the woods, powder measures and cappers (one of the reasons I don't shoot caplocks anymore) chief among my lost items.
A small horn--if can get your gun to cooperate, prime with the same powder you load with. I use 3Fg so that I don't have to have a priming horn and notice no difference other than that 3f seems to handle humidity a bit better.
Bullet board for rifle shooters: easy to make or purchase, but get one for 5 or 6 rounds. No one needs a 2X4 full of lead in the woods. This cuts down on wieght, too. Don't forget, 28 .54 caliber balls is an extra pound hanging around your neck. In lieu of a bullet board, just put the balls in a small pouch within your shooting bag, but not around your neck, and patching material or prelubed patches in there as well. The less junk you have hanging off your body the better.
If you have a smoothbore, consider preloaded cartridges. IN fact, if you have a rifle, you can also preload powder charges into paper tubes and then use a bullet board or whatever. Never had much luck ramming paper down a gouged-bore, therefore I try to avoid using a rifle as much as possible... :blah:
As far as cleaning goes, I'll use a pre-lubed bit of patching to swipe away bits and pieces, a dry edge of shirt or jacket to remove water if it's damp out. When I shoot, I always reload, even if I know I just whacked the heck out of whatever I shot, so, I don't take time to clean between shots. Maybe leaving the field for the day, but now we're talking back to camp or the truck.
Hope that helps. It ain't gospel, but it works for me.