I have to be careful when I'm in hunting stores, or I'd end up with a new back pack, vest, or batman belt every time I go to one! I have several different rigs for different types of hunting, here's what I've found has worked.
Fanny pack - when pushing the bush for deer, this is all I bring. I have extra shells, my range finder, my tags, my knife, my camera, and spare batteries in it. I also use this whenever I go to my stand, but I put an extra set of gloves in it as well.
Load bearing rig. I have 2 that I use when I want to bring more gear than I can fit in my fanny pack. I've looked at a lot of vests & different systems, but can't bring myself to buy one, because the 2 that I have work great. I use the old CF 82 pattern webbing, and the CF olive drab load bearing vest. If I'm out scouting during the summer, I'll wear the webbing, with several utility pouches and it carries everything I need. During the spring or fall, I use the vest if I need to carry more stuff.
If I'm wearing either of these, I have my backpack too, so I don't put anything in the rear pocket of the LBV, or use the butt-pack on the webbing.
Back pack - Any time I'm stand hunting, or going for a "long walk" type hunt, I bring a back pack. In it I carry; Extra jacket & vest for while in the stand, 12' of 1/2" rope, for making a drag if I shoot something. 50' of 550 cord, this is a small, strong rope that has more uses than duct tape. Gerber pocket saw. Small bottle of scent killer. Binoculars, if they're not around my neck. Extra gloves. Toque, I like to wear a light hat while walking, & switch when I get to the stand & start to freeze. Rattle bag. Seat cushion, tree stands get uncomfortable! Soft canteen, carries a lot of water, and you collapse it as you drink so it stays quiet. A snickers, couple Sweet & Salty bars, and if I'm going to be out all day, a couple sandwiches. A small pelican case, with matches, super glue, about 10' of duct tape wrapped around a small pencil, a back up compass, and if I'm in an area with cell coverage, my cell phone (call it a survival kit if you want). I also put a space-blanket in the back pack, but not in the pelican case.
During the rut, I'll carry scents with me, a bottle of doe in heat urine, and scent wicks, triple bagged in ziplocs.
If I'm planning to set up on the ground, I also bring a small folding turkey blind that stands about 3' high, and a folding camping stool.
In the spring & fall, I throw a rain-jacket in too.
MOST IMPORTANT - about a half roll of toilet paper, in another ziploc bag. When you need it, you want it, and you don't want it to be wet!
In a survival situation, the TP & scent wicks can be burned, and the ziplocs (except for the first one with deer pee in it

) can be used for water.
If I'm going anywhere with my backpack, I'll be wearing either webbing, LBV, or fanny pack as well. It all depends on the hunt. If I'm hunting coyotes, or deer hunting, any calls I have are around my neck or in chest pockets of my jacket/coat
If I'm hunting geese or ducks, I pack everything I need in my backpack, and leave it on the floor of the blind, or on the shore, and just wear a cheapo-elstic shell belt.