I've seen some works by people on the BlenderArtists.org threads and I was amazed at how much 3D models can look like cartoons if done right so I asked a friend there, bizla, if he knew anything about it. He did, thankfully and he told me where to find the settings for it and after fiddling with it a minute or so, I found out the following:
Your object's outline size is not gonna change if you increase the edge threshold. Increasing the threshold only makes it more sensitive to the mesh and if set too high, you will see your mesh (the wire structure every 3D object has). The following shows how it looks when you have t turned all the way up and set low:
Now, knowing me, I can't just leave it there and I always depend on HIS guidance on what settings to use and how much. Sometimes HE let's me find out through process of elimination, at others HE'll just tell me what to do, but this was a mix of both.
I wondered what would the cartooning feature look like on the piano and last night I played around with it quite a bit and these renders are the result. As you can see it's not perfect, but it looks cool anyway:
I am considering making a tutorial on cartooning, but we'll see what HIS plans are! Not making any promises here.
Have a great day!!