This is as per tastes. That being said, the larger the breasts, the larger the pallet, the bigger the design can be expanded upon. You can have anything you want written on your body. Some apply them as the bad-ass ladies, for the sake of earning some respect. If you want then try out simple fonts like this.
If you want something funny and custom made, then you can try out these styles on your breast with different tattoos. The tattoo is beautifully done to show of the beautify of digital animation in the form of tattoo art.