The kit I have at the moment isn't too bad, she knows by the tone of my voice when I say NO she's doing something wrong and stops.
My jill kit from last year was a nightmare, she had a terrible temper on her, hissing and biting hard. I have them out in the living room everyday and if she bit me id say no then put her into the cat carrier for 3-5 minutes, like a sort of jail. Then take her out and handle her a little, if she bit again she would go straight back in for another 3-5. She soon learnt biting me meant she missed out on her playtimes.