This is Brian and this is his bio/organic/light source shoulder piece. He came to me with the request for his skin to be ripped as if by claws with muscle showing underneath. The muscle would not be red but dark blues and greens, and after a few sketches we got the outline done.
First I drew out the best shapes that moved with his muscles to build the structure.
Then I added details, defined an edge, and added a light/power source in the long chamber on the top of the shoulder.
Once I figured out what colors I would be making each section, I outlined the sharpie sketch with the color of the shadow for that section so that I had the option of not using a black outline inside each structural segment. This establishes depth and leaves room to move boundaries in later sessions.
The entire process took about 5 hours from first sketch to finishing up the outline. Next session we will start filling in each segment of the structure and building up depths.