T.T.
Hi T.,
I have a 12 year old boy and a 6 year old girl. Both can be very challenging but my daughter is a handful. I found what works best for me is something developed in my 6 year old's school. I find echoing the rules given to her at school provide her with a consistant disciple. So here's the scoop:
It's called Wows and Zaps. When my daughter is acting up she gets a Zap. This means she has to go over to the white board we have set up and place an X in the 1st of 3 boxes. When she reachs 3 X's, she gets a toy taken away or time out (whatever is appropriate). When she is really good, she gets a Wow. These are also on the white board. She can use Wows to erase an X or she can save them up to 10 and exchange them for something special. I have this run on a week to week basis, so she always starts clean on Monday. I find by having her place the X in the box and then taking the toy away from herself, it makes her accountable for her actions and she can see where she stands, behavior wise.
It's been working so far. Hope this helps and Good luck to you!