Field training?

If you are humping a rucksack and living out of it (no vehicles etc), a bush stove or a jet boil to heat some shave water or coffee. A small compact type mirror to shave in. A small camp chair so you have someplace dry to sit. Second on MAJ Ken Landgren 550 cord and 100mph tape. I would also not go crazy with knives. A multi tool for emergency use and small folding serrated blade knife for general purpose use. I packaged my clothes in gallon zip locks in day "portions", contractor grade trash bags for the sleeping bag. Trick is squeezing out all the air you can. Bungee cords to help put up a poncho hooch or hold stuff to my ruck without attaching in. Headlamp with redlense filter. A new discovery, Aquaphor healing ointment if you are prone to chaffing. Black mechanix type gloves for handling hot or cold items they're grippy and allow some feel so you don't keep taking them on and off.

If you are operating off vehicles in a base camp (like the Brigade support area) with tents. I would bring a three foot strip of Astro turf to put next to my cot so I had a dry and clean-ish place to get out of my rack and get dressed and put on socks. I'd have a poncho liner to fold on top of the cot to hold the heat under me while in the cot. A couple wire hangers to hang up my gortex or fleece By my cot. Use the 550 cord to tie a line between tent supports with a series of loops tied for the hangers or a small battery lantern on a hook.

Going to the field in NATO, you have to bring your own coffee mug, a spill proof travel mug. They charge you for coffee/tea and don't provide cups.

Duct tape and 550 cord.

baby wipes
sunflower seeds