Under things, in things, & on top of things.
I am fortunate. My wife let me take over my son's room when he moved out. Over the years I have upgraded from the garage, to a small spot in the house, to my own room.
I drug home a "Caterpillar" transfer switch box, gutted it, and put multiple heavy shelves in it. I also replaced the feet with wheels, but it's to heavy to be rolling around without unloading first. I have a cabinet on the wall above my bench (From the old LDR nurses station). I also have a tall, deep bookcase that was left in a doctors office when they moved out. Stuff on the shelves in the closet. Ammo cans stuck all over.