Creating the handdrawn scribble look in Blender.
My goal was to get a working setup which is easy to render.
However this technique needs a special setup of materials, lighting, models and the Freestyle feauture.
So the short form is this is, use simple materials with luminance shades, models has to be relatively low poly and all this works when you use like really high contrast lighting setups.
The Freestyle setup is more or less a taste thing, but the importan part here, is to render the Freestyle as a seperate render layer.
Than the magic happens in the compositing task. It uses a posterize node setup to get the different seperated shades.
I used a simple Noise Texture to displace the Freestyle lines.