“Using the example of this ScfiFi Environment Concept I am gonna tell you a bit of how i approach and finalize a painting. There are several pretty different ways of how i begin with an image. The starting point can be a loose pencil sketch, a colour scheme i’d like to experiment with, a definite image i already have in mind or just the simple testing of a new brush i’ve created.”
http://www.cgarena.com/freestuff/tutorials/photoshop/scifi/scifi.html