On: Anime2Sketch: A sketch extractor for illustration,...

[jp555]

There are lots of very good techniques to do toon shading in Blender. Here's a few:

BEER NPR (MALT renderer) - https://blendernpr.org/beer/

Lightning Boy shader 2.0 - https://www.youtube.com/watch?v=8fHZcnTFYEI

Procedural hatching and manga shaders - https://gumroad.com/l/tcKOI