Small belt-mounted pouches for the things you need to reach without taking a bag off — pellets, cartridges, and the general dump pouch that everything else ends up in.
For airgunners, a leather or fabric pellet pouch on the belt beats digging a tin out of a pocket, and it stops skirts deforming against one another. An H&N safety case does the same job for a full tin inside a bag. Keep pellets dry — a damp pouch is worse than a pocket.
For cartridges, a mesh pouch such as the Beretta Uniform Pro drains and dries, which matters on the marsh or in steady rain; a closed leather pouch looks better and holds water. Mesh also lets you see what is left without feeling about for it.
A foldable dump pouch is the cheapest way to stop empties ending up on the ground.
Related: ammo boxes and carriers, cartridge bags, belts, air rifle pellets, waist packs.
