Texture
I was looking for realism with my model. Normally I generate textures, and Normal and Displacement maps in ZBrush, but in this case I only wanted to work with Maya and Photoshop and so I created all my textures there. The two most important materials for this character were the metallic shader and the suit shader. For example, for the metallic shader I created a Specular map from the Diffuse (Fig.04). I worked with the scratches masked in an empty layer. This fact made it easier because it allowed me to change their color, brightness and blend mode.
For the suit I was looking for something between leather and rubber, so I decided to work with the SSS skin shader (Fig.05). I used a Normal map from my personal library to get a tiny amount of porosity on the surface to better catch the light. For the Diffuse I just combined a simple layer with noise and a dirty texture that I painted using a custom brush in Photoshop.
Lightning and Rendering
To get more realism in the illumination, I worked with image base lighting because I needed some nice reflections on my model. But I found this was not sufficient, so for my final lighting setup I used three area lights set to a high intensity with quadratic decay rates, two volume lights for the wires and point lights for every light detail on the character (Fig.06).
The scene was gamma corrected with color management to fix any issues with the color. Alternatively I could have used the mia_exposure_simple (gamma = 2.2) attached to the camera.
The final render can be seen in Fig.07.

Fig. 07