Modular Raspberry Pi Mount

I'm using a Raspberry Pi in my latest project and I've been looking for a suitable mount.

I don't want a case, because I want access to the GPIO pins, and I'm not 100% sure of what else I'll be adding yet. I'll be using the camera, and probably adding a few buttons and maybe some lights.

There's a lot of cases on Thingiverse, but none of them seem to be exactly what I'm looking for. So I'll make my own! Hopefully some of you with the same needs and constraints may find this useful too.