In this video I'm showing you 5 cool cartoon tips in Blender. One of my favourite is the magic transparency, you can easily achieve this effect with the backfacing socket from the geometry node in the shader editor. This is the perfect way to make your transparent object look flat shaded.
If you like that outlined look and don't know how to make it then stick around because i show you that as well.
Secondary outline, no problem the wireframe modifier helps you in that.
I'm also showing how you can create hand painted stars but if you prefer proceduralism (is this a word?) you can find the node setup in the video as well.
The last two tips is about cartoon glass shader with cartoon reflections, it's tricky but once you have it, you can create a whole range of cartoon glass styles, flat or even semi-realistic ones.