This may be of some interest to those who have some woodwork skills.
That's cabinetry, practically. (-:
I bought some surplus "remote control" enclosures that were blocks of wood where they'd drilled out a pocket and cleaned that out with a chisel.
where they’d drilled out a pocket
That’s a good idea.
You could cut the center out then screw/glue on the top and bottom.
You would be able to create some interesting shapes too.
Edit: this is also an interesting way to make a box:
Great idea. And for those who don't want their prototypes to look wooden, search Ebay for a material called Foamex. It's a high-density PVC foam with a textured finish, available in the UK in 5mm thicknesses, in a variety of colours and I buy it in 4x8 foot (1.2x2.4m) sheets. It's easy to work with, it cuts easily with a wood saw, or a sharp craft knife, and it hot-glues beautifully.
Even easier, if you have a CNC mill.
Or 3D print them.
Just incase you where wondering that technique is called mitre-folding