Rock Effects!
by: oddhatter
This tutorial will assume that you're already familiar with Photoshop's tools. Despite what I might have said in earlier tutorials about this particular tool, this one will involving the dodge/burn tool a fair amount. =) This is because when it comes to rocks, you WANT strong highlights and shadows...that and really, it's much faster. For this tutorial, I'll be working with a picture that I drew of lovelymouse's Chakeya.

First, you need a flat colour on everything "rock". Generally, brown is a good choice.

Then, add the shadows. I had the burn tool at an opacity of 16% at this point, so that the shadows would not be TOO strong. A good tip to keep in mind would be... like everything else, rocks are affected by the direction of the light. So, it would be good to keep your shadows consistent. (don't put shadows randomly on the rock...consider where your light source is.)

Then add the highlights- same concept as the shadows. After the initial round of highlights and shadows, you might find that you want to go over them again and emphasise your shadows(or highlights) more. I like to grab a small brush and make little "squiggles" and random lines where the shadows are, it tends to gives the rocks a rougher and more "rocklike" look.

Another thing I enjoy doing is grabbing the airbrush, setting it to "multiply" at an opacity lower than 10% and dabbing at parts of the rocks with it with some green. It gives the illusion of moss sometimes, or at the very least, breaks up the drab "brownness" of the rocks.

After you have the highlights and shadows and the "moss" where you want them, grab the dodge and burn tools again and emphasise the highlights and shadows again. (obviously, if you want your rocks to have a softer, less harsh look to them...don't do this.) As you might have noticed by now, colouring rocks is really a very simple process that merely calls for lots of repetition=)

That's pretty much it, really. I hope that the tutorial was helpful to you!
Samples of rock effects I've done using this method!