I've become a stickler for replacing materials on figures and props for PBR rendering.  Not so much for actual realism but getting the most realistic response to environmental and legacy lighting.  I also do quite a bit of YouTube searches for Blender shaders, learning how to assemble Cycles-based shaders for Poser.  Quite helpful to simplify materials.  I also read available books on CG rendering.  One book I strongly recommend is James Burn's 'Lighting And Rendering', many valuable tips and tricks to populating your scene and speed up rendering.