I wanted to learn about camera mapping and explore different ways to color objects in the compositor.
I began with a rough sketch on paper of all the elements and the overall composition of the image. Then I sketched on paper every object separately, scanned them and made a collage in Gimp.
In Blender I roughly modeled them and projected every image on each object. Each shader is set to emission shader with a Light Path node ”Is Camera Ray” in case the scene would contain a shader other than emission. Depth of field in render and not as a post effect using depth map.
The file Open EXR Multilayer contains the different passes. I used cryptomatic to get an alpha of each object and colored with a ramp. Mixed the composited image with a pass of ambient occlusion to get some thickness.