Learnt a quick trick while doing this (iPad 2, SBP). I opened a hi-res document to get the sketch done, which gave greater control over brush diameter, then changed it to lo-res to get the full quantity of layers etc.
Awesome sketches Crit71. Btw, I looked up Danny Gardner's website and blog to see what you're talking about - stunning. Most of his environments are as detailed as his main focus...reminds me of the detailed scenery that Syd Mead does.
Your too kind dino =], and yes reminds me of Syd Mead too. Spaceship, windows colored in pale blue. Btw everyone is welcome to color and show the sketches I post, I don't mind, and I would love to see all your coloring techniques. I'm learning how to render now on my own cause I'm not in college yet, will be next year though. Sorry I don't have a scanner.