one cell for a modular tea shelf. this was made very specifically for my own shelf dimensions but I have been asked to share it and maybe it will help others as well, at least as inspiration.
I connected the cubes with super glue and with that double wall thickness they are strong enough to support teaware while still keeping a slim profile. 
If you want different dimension and dont want to make it yourself feel free to leave as a comment and I'm happy to add more versions! 
dimensions:
height (internal) - 93.9mm 

width (internal) - 111.0mm

depth - 90.0mm

wall thickness - 1.4mm