I've been noticing how important the shape of peoples' teeth are to their individuality. If you don't get the teeth shape right it can lose the likeness.
Below is my breakdown of a very famous set of chompers. First I figure out what the whole mess looks like as an overall shape - each person's bar of teeth has its own unique shape. Then I break it into sub-sections before drawing the individual teeth.
Here are some more beautiful and unique smiles.
I'm surprised more cartoon characters don't have specific teeth shapes-especially the supposed "realistic" features aimed at tweens. All the real live teen idols have very specific teeth. 
This guy refused to show me his teeth but he wasn't too ashamed of his nose.**BTW, I have resorted to bar teeth myself- especially on cute girl characters, but doing these caricatures is making me rethink things.
