Cool work, dude! I like all the anatomy and values you've got going in this piece. You might want to try using a more saturated color for the shadows, like a dark purple or blue, but that's up to you. The main thing I see missing is rim light. I did a really quick paintover to demonstrate.
![](https://d1s0ws440m13mk.cloudfront.net/original/3X/c/1/c12600559cf20dc266c5dc14b8b6325159f09c10.jpg)
I just took a small white round brush and highlighted a few edges of the orc's anatomy (only in important places where we want the viewer to focus, like the face).
After that, I used the same brush in black to emphasize the shadows between the folds of skin. Then I added some freckles to break up the skin tone. And...that's it
Super quick and easy trick to have up your sleeve.
Hope that helps. You're off to a great start!