Well, I read something that really opened my eyes about how we respond to kids throwing fits. If we just suppress the not-nice behavior by making them go to their rooms "till they can be nice," then they learn to just fake a smile, and they learn that they can't go to us to work through problems. They also learn that negative feelings are not acceptable, and they don't know what to do with them, and so they learn to suppress them. i dated a guy like that. Blah.
Anyway, Becky Bailey, the author of the book, titled Easy to Love, Difficult to Discipline, said that the cause of misbehavior is that the child doesn't know the acceptable way to get what s/he wants or to compromise, and if we never teach them, but just suppress their angry feelings, they never learn important emotional and social skills.
You can teach your daughter to keep a little stuffed animal with her, and when she's mad, she can throw it on the floor, but not at Mom. You can teach her that she may not hit or throw things at you or others. But when she throws fits, don't shut down on her. Be supportive through the fit, or just sit quietly by, and when it's over, talk to her in very simple terms about the issue she got upset about.
Really, the book explains it so much better than I. And it's so good at showing us adults what is going on in those little minds. Take a look and see! It will save you a lot of trouble in the end.
L.