>>9589347i have rubbermaid boxes of all types, tackleboxes, those clear plastic organizers, ikea glossy plastic boxes from various years, and even bought ammo boxes.
I like using smaller boxes, as they're easier to swap around and will fit almost everywhere, hence binging on ammo boxes when Costco was selling them. I also bought these to organize the figures better.
I'll use plastic baggies for some of the more delicate/smaller pieces, so everything stays together no matter what box it goes in.