it is hard to do, but...

IGNORE BAD BEHAVIOR.
Obviously if your child is hitting another child or being a bully you need to step in. But at home if your child is banging on something or whining, do not respond to it. They will stop. Then when they do something well mannered like say please and thank you, or ask a favor instead of demanding them, REWARD THEM. A reward doesn't have to be a new toy, children feel very rewarded when their good deeds are noticed. Praise them and simply say, "I really like how you are using your manners" or "Thank you for not whining about getting ready for bed." When they realize these actions are noticed and praised they will continue them and use those to get attention instead of being loud and obnoxious.