If you aren’t familiar with Zack Freedman at Voidstar Labs, definitely check out his channel. The latest project is a modular storage system, and it’s pretty awesome. They tile, stack and can be fitted with magnets to hold even more securely.
The models are parametric, so it’s pretty easy to design one to fit a particular need. He also made a whole bunch of designs, so if you’re lazy like me you can just start printing. The links are all in the video description.