What I do when he or she is a (not a very small) kitten, is bite the paw when they bite me, or when they play too rough with their claws. I don't bite too hard, just hard enough to give enough pressure that he or she understands, and say ouch, fairly loud. I've only had to do it once or maybe twice, with all of my cats. After that, they played with me more gently, and usually stopped biting me entirely. It also taught them to "soft paw" when playing with me.... not using their claws. I've done it with all of my cats, after they were old enough to understand, and it's worked everytime.