I enjoyed the modular features of sgnurf's original design called "DiceMasters - Cards and Dice modular storage" but the dimensions weren't big enough to fit my dice. I took the lid from the original design and stretched it a bit and worked with it from there to create two different trays.

One tray is empty inside like a normal box. The other tray has dividers to help organize the dice I'd use in a given game. This tray also has a small gap inside between the dividers and the wall, which I use to hold card reminders about spells or other such small paper notes. The lid has a hollow indent for holding tokens or as a small dice tray/rolling surface.

Each tray can slide onto each other like how the lid can slide onto the top of each. I'm still working on optimizing the space inside and the way the sliders work. But at the moment they seem sturdy enough and serve my purpose of a compact modular dice organizer.