What size box do you actually need? Smaller than you think. The ones that end up useless forever in a closet are the big ambitious ones that swallow a junk drawer in one gulp. The ones I reach for daily hold one category of one thing: the spare keys, the birthday candles, the cords nobody can name but everyone's afraid to throw out.
The honest limit here is that a small box is not a filing system, it's a holding pen, and if you ask it to organize something complicated, like a whole desk drawer of loose paperwork, it will just become one more thing you have to dig through. They're also bad for anything you need to see at a glance. A box with a lid hides contents, which is great for the stray batteries and terrible for the spices you're trying to cook with, since you'll end up opening six of them before dinner's ready. I learned that one after I put every spice jar in matching little tins and then stood in my kitchen for ten minutes looking for cumin like an idiot.
Where they earn a place is in exactly the spots every home has and nobody plans for: the top of a closet, the shallow drawer by the front door, a bathroom shelf with six inches of dead space above the towels. They suit small apartments especially well, because a few boxes of the right size can turn one deep shelf into three usable layers instead of one messy pile, and renters like me can stack and rearrange without touching a wall or losing a deposit. Winter is when I notice them most, when the light's low by four and I don't want to be hunting through a drawer for gloves in the dark, I want to open one box and have the right thing in it.
Measuring is simple but the mistake is always the same, people measure the space and forget they need room to lift the lid or slide the box out past whatever's next to it. Measure the shelf depth, subtract an inch for your hand, and measure height with anything already stacked on top in mind. Buy one, live with it a week, then buy the rest of the set. I did the opposite once, bought eight matching boxes before testing a single one, and three of them have sat empty in my coat closet for over a year because they were never the right depth for anything I own.
The good ones have a lid that comes off clean in one motion, no wrestling, no catching your thumb, every single time you open it.