As for stylized textures, you could search around on the forum here, lots of resources on how to paint textures, for example https://polycount.com/discussion/117119/a-pack-of-textures-painted-using-hand A fairly common strategy (and quite successful) is to use Substance 3D Designer to craft a height map, then alter that to…
I've been working on building a library of stylized materials inspired mostly by the Overwatch art style to get more familiar with the software. https://www.artstation.com/artwork/45E1k