Since posting my Thief illustration, many people have contacted me asking about my processes and how I created the image in 3D. So to explain, I have split up the 'layers' of the completed illustration which will show how the everything was put together. Even if you have zero experience in 3D and those terms mentioned below make absolutely no sense, hopefully you can still understand the processes visually.

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1. Diffuse render - fullbright, solid colours
2. Ambient occlusion render, original
3. Ambient occlusion render, colour adjusted
4. Diffuse render(1) * ambient occlusion(3)
5. Shadow render, original - very intense directional light & Lambert shader
6. Shadow render, cleaned up & colour adjusted
7. Diffuse render(1) * shadow render(6)
8. Diffuse render(1) * ambient occlusion render(3) * shadow render(6)
9. Final image - completed with finishing touches
(* = Layers stacked with multiply mode in Photoshop)
...and here is the full-sized final image again.

Click for larger size.