Another thing I've enjoyed seeing out there is dice which give a sense of place: tiny landscapes, galaxies, and so on. So naturally I've been putting together some dice which work with those ideas, with a big boost from 3d printing for some of them.
The one that didn't use 3d printing involved the use of a series of hemispherical molds. I started with making a mottled blue and green hemisphere with tinted resin. Then I glued the flat side to a stick and suspended it over a slightly larger hemisphere filled with clear resin. Once that was set, I painted clouds directly on the resin, so the cloud layer is slightly above the "ground" surface. That went into a mold half-filled with black resin with a few bits of glitter thrown in for stars, then topped off with more clear resin for night and day sides.
One of the nice things about this is that it's all resin, save for a trivial quantity of paint and glitter, so it's as balanced as the mold allows. The remainder are based on terrain out of the real world. It starts with the Terrain2STL generator, which uses GIS data underlying Google Maps to create STLs of a selected area.