This is my favorite part. My main reference with texturing was the DOTA 2 Character Color texture Guide
with slight modifications. First, I built the layers and folders hierarchy in order (bottom to top), working through color, textures, AO, FX, light, correct and helpers. To clarify:
? contains the layers created with the Solid Color, allowing me to change their color anytime
? material textures (metal, skin, fabric, scratches)
? the ambient occlusion maps, added with the Multiply setting
? contains the detail maps, cavity and curvature, blended with the Overlay
? a diffusive texture requires light for an additional volume. I used the light from the Green channel of the Objectspace. The folder Blending type is set to Soft Light, the contained textures are set to Screen, and, if the light is too dim, I can fill the top layer of this folder with gray color with R90 G90 B90 screen settings, and, varying the alpha, I can get rid of the excessive darkness
? I created 3 layers in this folder: Overlay, Multiply and Color, and then I used them to add light, shadow, or correct the color
? contains the scanning and the color selection mask
Of course, I could have added some more scratches, dirt and damage, but the contest rules demanded that I present the character in the brand new, shiny armor, and so I did.
That's how I do my diffusive texture; the specular map is much simpler to do, provided that I base it on the diffusive, removing AO, light, and correct folders. I added an extra contrast using the curvature maps, stacking them as much as needed to receive the required effect. The blending type was Overlay.
This is how the adjustments appear