The posts above cover the basic necessities very well. I carry and extra mini mag light with some spare batteries. I also carry among other knives a " Wyoming" knife that is really good for splitting the hide and peeling it back. The orange tape noted works great in the daylight but the reflective (called glint tape in the military)tape is a great idea. A blue filter on a flashlight could be helpful for finding blood in the dark. I also carry a Camelback that fits in the main pouch of my pack. Boning out an elk at high elevation and humping some of it back to camp is an exhaustive drill - hence plenty of fluid. There is a difference between deer and elk/moose game bags (thickness). I also carry about a 100 feet of parachute cord for hanging game bags in trees if repeat trips are necessary (it doesn' t take up any room nor does it weigh much at all).
Some emergency " snivel gear" is a wise part of your pack if your range several miles from camp on foot especially in a wilderness area. I pack two very compact light weight space blankets and some fire starter material with a magnesium flint like piece of metal and water resistant matches of course. I have a wool sweater as part of this emergency/stay in the woods kit.
I have an external pack frame (Cabela' s Alaskan Guide series) that I attach my day pack to. It has a fold down shelf that makes attaching a hind quarter or front shoulder to pretty convenient. By the time you empty the pack of the game bags, etc. the day pack collapses down pretty flat.
Along with whatever snivel gear is appropriate for your hunting style, add a couple protein/energy bars.
Regards.