Hey all!
Recently, I was prompted by GOD to look into making stronger backgrounds for toon objects and that meant higher sample rates and smooth shading - none of these are good for toon-shading, because they all produce smooth colors and areas, not hard ones, but through about an afternoon's scene building and a night's compositing, HE helped me get it done, so now you can get a result like this:
Now, this may not look like much, because it seems like a silly example, but you have to look beyond the scene and into the technical. For example, look at the shadow of the pillars - they are smooth, while the toon shaded object remains clear, or sharp. You can also see that the shadows that the toon shaded objects cast is also smooth.
Also note that compositing works just as usual. This method, though simple, is extremely easy to miss something. Let me explain - it used many features to separate as well as join the scene objects, but not one of them is complex. The amount of things make it easy to miss something.
I really hope to be teaching this method in a video tutorial soon, GOD willing! :D
Have a great one and GOD bless!!
I leave you with a test scene:

Tree scene (C) 2015