Personally, I don't like to have too many charms on my bracelet 'cos I'm afraid it'll end up getting in my way and they'll scratch one another.
So far I've only got 2 charms on my Tiffany's bracelet -- one's the Return to Tiffany heart tag charm and another's the Tiffany 1837 circle charm with black enamel in the centre.
I plan to buy another 2 charms in the near future though, to complete my "ideal" Tiffany's bracelet!
Btw Stephanie, not sure if you're already aware, but if you go to the Tiffany's website, there's this part where they let you drag the charms and place them on a bracelet, so you can kinda see how it looks like. Maybe that could help you decide?