Hello digitalseed,
NPR, or non photoreal rendering not as bad as you would imagine, but can be a broad subject. This site actually has a course on the subject, I believe it’s called cartoon rendering with freestyle. Freestyle in blender is a good option for the outlines, however the settings can sometimes be tricky. For shader setups, if your using I kind of simple toon shader there are many options for this. However if your wanting some texture to your shadows such as, airbrushing or magazine style cell shading (the little dots) blendernpr.org has some good resources and community ideas on the subject. I found blender render in older copies of blender (pre 2.8) a good option, and for 2.8 EVEE they’ve added a shader to RGB node although I have not tested this, but both of these should allow you to manipulate shadows more. In, addition when adding texture files try some different inputs for texture mapping such as view or camera rather normal UV mapping.
