Anyone have any tips or tricks to make the smiles more natural? The mouths bother me so bad, specifically when you have an almost real looking character. Also I noticed human mouths tend to behave different that iclone. For example, most smiles the upper lip raises in reality. It just bends in cc4. 

This is something i'm also curious about. I'm wondering if it can be adjust with the facial expression editor of if facetool is the best way to go.

Sorry for not being a huge help here, but I got my experience in that from DAZ studio.
The main thing is to add (keyed) morphs to your smile, controlled by a main smile slider.
To have it keyed, might be important, in order to have that smile look best at any point of your settings.
This will be a lot of work, but it's worth it.