I have finished the sketches and 3D model for the background, now the process is more linear. (Literally.)

I started lining the drawing, added some hatching and texture, followed by flat colors. I wanted the drawing to have a cozy/harm look, so I picked warm colors.

Once that was done, I started working on the lighting and shading. It was a battle because there were two sources of light, one outside and one indoors. Not to mention that there's two planes, one where my "avatar" stands and one where my memories are portraited. I eventually found a solution.

Finally, I adjusted the colors to pop the contrast, added some darker shadows and finalized it with some highlights, sparkles and paper texture.

Hope you like it!