A spoiled brat can be intimidating and frustrating, but they are not actually as hard to handle as they look. This is because at the end of the day the spoiled brat is a child and you are an adult. You wield all of the power in your relationship, and if you remember this, stick to it and set clear rules and consequences of breaking those rules you should be able to handle a spoiled brat. It will try your patience at times, but if you stick to it you will be surprised by how quickly your spoiled brat cleans up her act.
Set clear boundaries with your spoiled brat. This way, she will not have ignorance as an excuse. So, tell her "if you throw your plate, you will be going to your room for 10 minutes." This makes a clear connection between throwing the plate and going to her room. She can choose to behave.
Stick to any discipline you promise. If you follow the Step 1 example and he still throws his plate, he needs to spend time in his room. Otherwise he'll learn that your bark is worse than your bite and that his actions don't actually have consequences.
Say "no" more often. What's more, stick with it. "No" should mean exactly what it sounds like, not "only if you ask me ten more times," or "no, unless you have a temper tantrum." Misbehaving children need to understand that when you say something, you mean it. The way enforce this is to show them with your actions.
Avoid bribing your child. It may seem like a quick fix to say "if you stop that, I'll give you candy," but when you do this you are just reinforcing bad behavior. Bad behavior needs to have a negative consequence; a positive consequence just reinforces it.
Ignore your child when he does inappropriate things. You don't need to discipline all the time, but rather just discipline some of the time, and at random so that he doesn't know when you're watching and when you're not. This will keep him on his toes all of the time and also keep you from getting exhausted.