I don’t think CGC has anything specifically on NPR aside from maybe a basic toon shader in the materials course? Lightning Boy Studios on Blender has a pretty thorough walkthrough of their toon shader. The videos are older but the basics probably still apply.
I’ve been putting a bit of research into this subject, mostly just piecing together information from a variety of YT videos. The actual shaders almost seem like the “easy” part since apparently the real pros deep dive into editing normals to get the shadows looking smooth. If I remember correctly, CG Cookie recently posted a video on their YT channel featuring a talk by DillonGoo Studios. It’s more about their workflow but there were some good take aways – I thought their “flattice” rig was particularly clever.
