I wanted to make a dwarf planet, using elevation maps from the Moon, (and maybe Mars?) for realistic craters. I thought it may be helpful to save out the steps, so that others can follow along. Tutorial time!
You will need:
The 3D program of your choice, it should support displacement maps.
A high res source elevation map, these are available online.
An image editor that can edit 16 bit grey scale images.
I started with a slice of elevation map from the rear of the moon, (less recognisable), in the proportions of 2:1