The best way to help teach your child to distinguish right from wrong is by setting clear limits and enforcing them consistently. If you feel as though you're slipping into a power struggle, step back: Give your child a time-out or simply tell her you'll deal with her in a few minutes—and don't decide on a punishment until you're more calm.
When she does break the rules, respond in a way that won't deal a blow to her self-esteem: Ignore attention-getters like whining; give a brief warning or scolding for minor infractions (such as jumping on the furniture); issue an age-appropriate time-out to stop aggressive or antisocial behavior (like biting and hitting); and use logical consequences, such as putting their toys aside for a day whenever your kids fight over them.
But discipline isn't just a question of punishment. It's also about modeling positive behavior—like remembering to say "please" and "thank you" to teach your child the value of manners—and praising her when she's been cooperative and helpful. By spending extra time with your child, you can minimize whining and other misbehaviors triggered by a need for attention.