I pack the accordion style tube from my whitetail grunt call. I used it last year in CO to direct some water into a Nalgene bottle from a near dry creek.
Black and Mild cigars. I’m not much of a smoker, but they keep the bugs at bay when gutting.
Fruit flavored tootsie rolls. I stash a few here and there. They cut the dust and dry mouth if you run out of water, and their wax paper wrappers are good fire starters.
A small headlamp like the petzl zipka. This works as a headlamp or task light, but also really comes through in red-flash mode to help you find a downed animal you are packing out in the dark. Just set it to flash, put it at eye level and facing your angle of approach, and it is way easier to make that second trip in the dark.
I also carry some of my Dad’s ashes. On every hunt. He developed my love for the sport, it’s the least I can do.
Reflective markers that clip on tree twigs. Good for marking a blood trail or marking a trail you are going to hunt again. Non reflective surveyor tape is essentially useless in the dark .
Sitting pad as well made from neoprene waders. Besides sit on I use it to stand on if I have to get out of boots or pants and its a small clean place and that is welcome when there is rain or there is snow.
I've been packing a small camcorder with 35x lens. It's great for zooming in on critters when scouting. It's then possible to take video home to look on the big screen to size up critters. It's amazing what video will pick up that is missed when looking through binos or spotter!