I use to have a system that I used that was like the MOPP levels.
Level 0 Pistol/ Rifle loaded & Flashlight.
Level 1 + Bodyarmor, helmet & individual equipment (ammo,med kit,commo ect).
Level 2 + Ruck/ Assault pack & extra water, food & ammo.
Level 3 + Mission equipment, pyro, demo ect.
Level 4 + Special equipment, 3day's of supplies.
But to be honest I now just have three packed GO-Bags
Assault Pack Extra Batteries, ammo, medical kit, basic tools and map.
Ruck 3 days food, water, clothing and sleep system, sheltor ect.
Duffle bag All my disappear for 30+ days gear. (two actual duffle bags)
This system works the best for me, b/c 90% of the stuff I am doing I can grab my assualt pack, if I am going camping I D-ring the assualt pack to the top of my ruck. If I ever have to go away for a more then 30 days I have the two duffles that have everything I could ever need (fishing/hunting, water treatment, clothing soap, personal products ect).