A map I made that shows off what I've learned so far about terrain, and maintain playability.
It's the first map to feature more than 4 cliff levels (though it's an illusion), and also has a bunch of nice waterfalls, weather effects, and texturing.
Mains are at 12 and 6 on the higher ground, the natural is easily defended as it is inside the main choke. The 3rd is easy to take, though it opens another entrance into the main and is vulnerable to drops within the stream.
The High Yield Minerals are out of the way but must be guarded against easy attacks from the ground above them.