I have been working on understanding post process shaders and my first experiments have been to emulate a manga look and the outrun/vaporwave style. The main experimentation I've done so far is setting up the cel shading with a Screen Tone applied using Post Process materials, isolating elements in the post process volume using Custom Depth Stencils, and using Light Functions to add a hatching texture to the shadows. These two scenes were done using mostly the same master shaders. I used material instances to modify the master shaders to get the two different looks.
All of this was done in Unreal Engine 4