Don't make threats that will make you suffer too. "Don't make me turn this car around!" Pick punishments that benefit you. "If you continue, we're going to Grandma's instead of the movies."

When your kids are in some trouble and crying bitterly, don't bail them out of trouble. It will reinforce bad behavior. Establish clear rules and meet out punishment when necessary. 

If you suspect your kids haven't done their homework, ask many specific questions: Which subject? What did you learn? How long did it take? What was the hardest part? The act of maintaining an elaborate lie will discomfort them. Telling the truth will be easier.

Kids are master manipulators. They will play up their charms, pit adults against another and wail loudly in public. It's your job to keep up with them.

For siblings who refuse to cooperate with each other, assign them a task that they can do as a team, like picking up the toys.

Over time, this will compel them to work together.