I also use a small backpack as a fanny pack doesn't cut it for me.
In it I put:
A couple of bottles of water
A zip lok bag with toilet paper
A zip lok bag of paper shop rags
A zip lok bag for tags and other important papers
A couple of extra zip lok bags for liver and just in case
Food for the day (a couple of sandwiches and some snacks as I usually go out all day)
Compass always (I've gotten turned around in familiar territory in a severe storm once, ONCE)
Harness type deer drag (way more leverage using your upper body in addition to your arms)
Orange trail marking tape (in case I have to track a deer any distance)
Flashlight (I don't like the hat brim lights, too much glare for me)
Small first aid kit (bandaids, neosporin, aspirin, antacids)
Small survival kit (space blanket, matches)
A 50' length of clothes line (you never know)
A light rain poncho (I will wear rain gear if I know it's going to rain)
A 3" folding knife w/ a rubber handle (bigger knifes are too cumbersome for me inside a deer)
A folding saw (for sternum and small branches if neccessary)
A gerber rib spreader (I tried a friends' and went right out and bought one)
A pair of ratcheting garden shears (for clearing shooting lanes and small vines and such)
Extra ammo
Grunt call and bleat can
Small binoculars
A bottle of estrus doe urine (I prefer the spray bottle)
A film canister with cotton balls soaked in doe urine
It sounds like a ot but really doesn't take that much room up.
After I put on my back pack I put on my seat:
I attached two shotgun slings to a camo folding chair with a back on it. When I get out in the woods I unfold my chair and set my back pack down next to it and I'm all set.......................................ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ