My daughter was very ummm, spirited when she was younger, and we had some boundary/respect issues as well. We worked with a counsellor to help us deal with the issues at hand, and he had some great suggestions.

What worked best for her (and me) was a Reward system, rather than a disciplinarian one. At the beginning of each week, we sat together to discuss and set a goal, then she got her choice of reward (as long as it was reasonable).

For example, the goal one week might be to use nice words instead of mean/disrespectful words. She would be allowed to make mistakes -- because we all do -- and a limit would be set right off the bat on how many times she could 'forget' the goal. Usually it was somewhere between 2-4 times.

Sometimes the reward she'd choose was as simple as a bus ride to town, or a walk in the park. Sometimes she'd choose a movie, or a few dollars to put toward her savings account so she could get something down the road that she really wanted. That was a real motivator for awhile! :-)

Good luck to you! It's definitely a challenge, but the results are absolutely worth the effort!

MHH