How would i do it?
I want there to be clutter items and such you cna pick up but the main thing is, put something where you expect to find it.
Ammunition should be found in ammo crates, corpses of enemy/friendly gunmen, or in someone's stash or safe.
Spoons forks, table ware in kitchen oriented cabinets, or mess halls.
Lockers should be full of paper, clip boards, clothing, possibly some weapons. Some more random crap and such that people put in their personal belongings.
Desks full of paper and such, maybe some gum.
Safes should be full of something valuable like, ammunition, drugs, money, etc.
Batteries, machines, etc should usually be found in a repair shack or some kind of supply closet.
I don't want gold coins on dead animals, or someone carrying around a toaster on their person. Or to find food in some locker outside. Or to discover someone keeps machine parts in a refridgerator.
Not every pack and sac has to have something of interest but if it should hold what it logically holds.
Of course some weirdo might have a fork collection he keeps in his safe, Or someone keeps alot of raw meat/food stuffs outside in a trashbin for some animals, just odd things like that from time to time.