some people may not like the technique, but it does work... it's hard to explain, but this is where i learned (learned is that even a word? or is it learnt? hmmm i'll have to google that)
http://channel.nationalgeographic.co.../dogwhisperer/
just go to that link, and click on the top for videos then on the left choose by program, then click on dog whisperer. There will be a whole slew of short clips that show you different techniques to use... i use the human dog bite since i'm a little scared of the choker thing with a yorkies cuz their prone to collapse treacheas. I do use a regular collar and hold her with the collar to keep her in place, then do the human bite (sort of like a little jab) but check it out first... it totally worked for me...