I do all my own training, having bred collies for 25 years I have lots of expreience. Collies are so smart, they should probably be training me, perhaps they are and I just don't know it! I will use the "roll" technique on the older pups if necessary, and it does seem to work.
There are a couple of things that I do to teach the smaller pups not to bite people (in play, or course) that some might not aprove of. When I feel any pain, or even just feel the teeth on the skin, I shout a loud angry "NO" instantly and then stand up and stop playing or petting. Most of them will catch on after a week or so, they know that it makes me angry and it deprives them of my companionship.
If that is not effective, I sharpen up my reflexes and then, the instant I feel the teeth, I tap the pup with 2 fingers, lightly, on the head right between the ears, just to get their attention. This is accompanied by the NO and the stoppage of play or petting. Another option is to hold the pups mouth shut for about 30 seconds while you scold in an angry voice. Usually some combination of these things will work in a week or two, if you are consistant and patient. I feel it's better to teach the pups this BEFORE they go to new homes, then they don't get in trouble with their new family.
And I don't think it's abuse, you have to let them know that you are the alpha dog, you are angry, and biting people is a no-no. The bigger they get the harder it is to control the action, it is so deeply ingrained as time goes on. So start very young, be consistant and firm, they will learn.
Marcia P. and the Bonnie Collies