My cats only bite when they are playing, and when they do, I freeze and say loudly and sternly, "NO!" and when they back off I wait a couple minutes before we start to play again. Even at that, it's only Nutmeg and Bassett who do it. Tilly I don't think has ever bitten anyone, except she's threatened it at the vet!

Nutmeg does, however, lick ALL the time. I HATE it but she's always done in and I haven't been able to train her not to.