I'm pretty good at the 3d software, but I don't have an extensive art background to reference. Ie., I'm flying by the seat of my pants. Here are some stops along my pants flight:
- I'm great at digital modeling but I've never made physical dice myself. I do have a 3d printer to make the initial model, but taking it the next step (making a silicon mold and resin casting) I would leave to someone else.
- Currently your dice have sharp edges. Some people like that. We could also easily round them.
- Hollow dice, like a cage made of some squiggly or zig zaggy pattern are doable, model-wise. Good for digital tabletop but hard to manufacture.
- We could also explore stylized versions of your symbols. Probably plus and minus should stay mostly the same, but there's a lot you can do to a triangle and a circle and still be recognizable.
- I'd use Blender for modeling, shading, and exporting the dice and Inkscape for the symbols.
I also like teaching, so if you want to play around yourself, I'm happy to point you toward a usable workflow. Tbh that's my preferred path, because it takes less work for me and I'd feel like I contributed what I wanted to this project.