It's been a little bit. No, I HAVEN'T fallen off the horse! I've been working on redesigning my website. I'll let you know when it's up and ready. Perhaps I'll work on that some more today...
Anyway, I just finished doing a study of a sandstone arch slightly buried in white sand. It is almost entirely hand-painted. The only photo texture I used was a very faint noise layer for the bricks. I did sample a quick palette from the original photo I used for reference. I kind of see it as cheating, but as long as I'm using it to learn, I don't feel too bad, and it's a happy medium between devising my own colors and sampling every single color from a photo.
What I learned:
-Be minimal with line work in bricks. A little detail goes a long way. If you need to draw in the lines for a brick wall to help you keep it well modeled, do so very lightly. save the extreme darks for the end
-When dealing with a sandy environment, it really sells the believability of an object if you pop some of the sand in cracks/crevaces. This piece felt very flat, until I did that. I'm used to doing that with dirt, but sand/snow and the like get a noticable build-up
-If all of the stones are of the same material, you can get away with blocking it all in with one color, then use subtle hue variations of it to set the bricks apart from each other. After that, you can also use a rough scattered brush to start speckling the color of one stone on top of another. This helps to unify the wall, while still showing it's composed of separate bricks
Photoshop ~1.5 hrs.
I got some solid crit from my good friend, Daniel Landerman (see his blog in my friends list). Namely, don't use a low opacity brush and stack it. Use a high opacity brush and make every stroke count. This keeps stuff from looking blurry, it's faster, and it gives a better knowledge of color usage, with practice. I totally agree, and my next piece incorporates that technique. He also agreed that my perspective is a bit off. =)