LMAO I understand he may need them so it really is a necessity. I alway enjoy Hardcastonly's post but this one is the best. Oxys and granola bars! Sir, I WANT TO HUNT WITH YOU!

But seriously Im going with....

A good trusty light. Chargeable is nice but you better make sure it charged and I also like to take a backup power pack. If you choose a battery powered light carry extra batteries.

A compass you know how to use.

A good quality sharp knife.

sorry for going off topic some here, but I find it funny how so many folks list things like there hunting in middle of no where where life and death decisions have to be made and gear need's to match them

when 99% of hunters according to study's tend to hunt less than a 1/2 mile forma a road, with MOST hunting a LOT closer than that! LOL

personally I think the best thing you can take into the woods is common sense, and have some SKILLS That allow you make good decisions when out there!
as in LEARN what things are,in your area's you hunt and learn how to stay safe in the first place in your surroundings!
gizzmo's and gadgets can all fail, but having some fall back skills you learned and know, can many times over come a LOT of things, and keep you alive more than any ONE Item ever will IMO!

survival in BAD times , tends to be a combo of things, and never just one!, plan accordingly to where you hunt , learn things before you go, and odds are you will always make it home, unless your health fails
which also says, Maybe get in shape before heading out there, something I am sure many of us take for granted, based on WE USED TO< do"X" but as we all age, things don't work the same way LOL
admitting our skills and condition in an HONEST Way, is some times needed to stay safe too!

Good crossbows, Rifles, Binoculars, GPS trackers these are the important accessories on my point.
Best binoculars for bird watching : Vortex Optics Viper HD Roof Prism Binoculars

IMHO

1st. Good pair of comfortable boots
2nd. An appropriate First Aid kit with tourniquet and the knowledge to use it.
3rd. Good rain gear (poncho or rain suit depending on your location)

Decoys are important. Very important. Whether you are hunting for waterfowl or turkey hunting. Not utilizing decoys for your hunt can be one of the biggest mistakes you can make as a newbie. If you want to fill your bag more often, you need to have decoys and use them to their fullest potential.

This question is too vague for simple answers. What the most important accessories are depend on where and what you are hunting and the time of the year you are doing it. I think the OP and the members here would be better served if the question was what are the must have items to hunt for (Name a Species) in, (name a state or country and the area, mountains, canyon country, high desert etc.) in the, (Name a season of the year)? That way the advice given will not be general but specific to the species, place and time of year.

A trail camera is a good accessory. My father uses one.

Sporting arms are not an accessory they are a necessity.

Patience.
Patience to allow yourself to put the time in at the range to become properly familiar with gun handling and marksmanship.
Patience to understand that the more time you spend in the woods, the more observant you become and the more you see. You only become a hunter slowly through your own experience.
Patience to understand that once you pull the trigger, the bullet is unstoppable. Despite what the media experts impress, a hunting season doesn't happen in a 1/2 hour show and hunting isn't a competition.
After that, almost all the gear is a matter of compromise, and without a bottomless bank account, you build the gear slowly. You may adjust your outings to the weather due to your gear for a while but that teaches...patience.
After that, I agree that good footwear starting with the socks and going out is foremost, but that doesn't mean you have to spend a lot. Make sure they fit properly with good socks and you can walk all day.Next for me probably was decent non cotton long underwear, followed by a good pair of gloves/ mittens.