I decided to pick up on one of my older maps (one of my first, in fact) that I never really finished. I tried colouring it once before, but I had no idea how to tackle it.
Here's a new attempt, with much taken from Torstan's tutorials.

The old version:
cen_heddan_map___wip_by_dwylaw.jpg

And how it looks at the moment:
a7580c1a063e76f126cdf305f3fa88d0.png

Shading the rock that this town is on. Black and white (brush pressure sensitivy set to pen pressure) on two overlay layers to build up the core shadows and highlights.