Time was, parents threatened unruly children with a lump of coal for Christmas. Today's kids  -- who barely know what a lump of coal even looks like  -- often hear a new spin: If you don't pick up your toys (or clean your plate, or say you're sorry), "Santa won't visit us this year!"

It's an understandable tactic, but not a smart one. "Discipline should be about teaching, not threatening," says Roni Cohen Leiderman, Ph.D., a develop-mental psychologist in Fort Lauderdale, FL. Invoking the wrath of St. Nick  -- or the Easter Bunny, or any other beloved icon  -- as you scold your kid takes away from what should be a happy childhood notion.

Plus, the consequences of your child's misbehavior should be logical, says Leiderman. Denying him Christmas presents long after a misdeed teaches him nothing, not to mention that it's just plain cruel (if you can even bring yourself to do it!).

Dragging doctors or policemen into the fray is also a bad idea. After all, you want your child to build trust in authority figures, not learn to fear them  -- tempting as it may be to pretend to call the cops when he throws a king-size tantrum.

So when he misbehaves  -- say, he dumps his food on the table after you warn him not to  -- give him an immediate, related punishment, like sending him away without dessert. He'll learn what happens when he acts out, and can still enjoy no-strings-attached gifts from Santa.