more contrast, use the high contrast colors to define the planes of the rock. I'd also  think more about your character design, reshape those rocks into something more powerful or dynamic, and less like a stumpy snowman.

Looking at your work, I think your aiming for a smooth looking golem. But I'll make an example for that later.
 An important thing to keep in mind with art is that color and form provide  depth. Shading needs to be controlled, thought out, and concise. So you may want to start out with cleaved rocks for practice to get the idea. They are relatively easy to make because the planes usually require only one type of color and lighting is easy to setup. Here is a quick example I made for you to study:
 

(Also, if any plane is jutting out of the rock do not erase it. The silhouette of a rock is irregular.)

Edited by Jumble - 04 March 2012 at 5:35pm

you're not shading according to a light source. it looks like flat camouflage. pick a direction for your light source and shade accordingly. first lay out some sharp planes though, you're still working on a formless blob.

Edited by cure - 05 March 2012 at 7:39am

Much better. The textures look a bit too soft though, try making it sharp and jagged like how Jumbles example looks.

Hey Aastikya ^__^ I'm glad to see you're still at it! Good work!

this new rock golem is quite the improvement from what you first started with. wow, what a difference =D

I think, for now, focus on the other aspects (like the face features and other things that your original picture had) and then come back to the whole 'rock' thing and texturing once you've laid out where the rest of stuff goes. you have a solid template to work from for now. =)

Keep at it, you're doing well =)