I have one of those "under the bed" plastic storage boxes which I've sectioned off into six equal slots with cardboard, in which I store a good chunk of my plastic minis (mostly D&D Minis, but a fair selection of other stuff like creatures from the Toobs line, plastic spiders, and the like): undead/constructs, outsiders, vermin, animals, aberrations/magical beasts, and elementals. Then I have some smaller plastic containers holding my other D&D Minis: humans, dwarves/elves, monstrous humanoids, reptilian humanoids, dragons, and oddballs (to include oozes); those are stored in a dresser drawer, while another drawer holds the bigger plastic figures: the larger dragons, dinosaurs, a dire elephant, a pair of giant spiders, a giant bee, my Beholders boxed set, etc. I try to match the mini with the creature it represents in the adventure; if there's no real good match, I'll resort to creating a stand-up token on card stock. (Those get saved in flat plastic contains that used to hold oversize cassette-type tapes.) On rare occasions, I'll make my own "mini" out of poster board, construction paper, or colored card stock: I've done a stone colossus, wood colossus, zygomind, and "walking brain" in such fashion.
We're purely a face-to-face setup, currently on hold due to COVID. But we make use of battle maps (I've got about three dozen of Paizo's Game Maps and Map Pack sets) and I make my own geomorphs: paper or cardboard with 1" grid lines for smaller areas or the back of a desk calendar page gridded out with 1" lines for larger areas. The homemade geomorphs get filed in manila envelopes in another "under the bed" box, and the calendar pages get rolled up inside an empty toilet paper roll with the adventure name written on it, then stored in a dresser drawer (one of two, nowadays) in my gaming room. (I've found multiple uses for several of the geomorphs/calendar maps; each time the new adventure title gets added to the envelope/toilet paper roll.)
I also have a small collection of unpainted metal minis from decades ago; my grown son paints some of them on occasion, as well as a bunch of plastic minis he purchases for his own campaign. Those are hanging in three display cases on my gaming room wall, while his sit on his dresser in his bedroom.
Johnathan