Have you ever seen Supernanny? She goes into a new house and has the kids listening to her quick smart.

Kids need consequences. Tell her "If you are good, you can go to the park" or whatever she likes doing. "Not good, then no park/desert/favourite toy" ect. Supernanny also uses time outs, but my son used to go and sit down and count for himself and thought it was a big joke.

My son plays up over dinner and refuses to eat. He is allowed a car at the table, but not play with it and as soon as he doesn't eat we take the car away. He understands that if he eats he gets the car back.

Consequences, consistency and following through on threats are key.