I think I've used this title before but we do it a lot.
Yesterday, Alex threw such a massive tantrum at school that they went to their big guns: taking away his van ride at the end of the day. He loves riding in the van. Instead, I had to go pick him up. The point was to avoid rewarding the bad behaviour with something he liked. Even if the reward is a regular part of the day, it can still be reinforcing.
Nathan also had a difficult day. Lots of shouting, stamping of feet and refusing to cooperate. He didn't want to come home in the car, he didn't want to leave the car to go in the house, he didn't want to say hello to Nana, he didn't want to put away his things, he didn't want to get dressed for art class, he didn't want to get in the car ... you can see how the list goes.
With Nathan it was a little trickier. He likes art class (most of the time), so would it be rewarding to make him go even if he doesn't want to? On the other hand, he shouldn't learn he can get out of obligations by behaving badly. With this, I went with what I feel is the key issue: control. Nathan and I are locked in a battle for control and I will not be losing. If he asks politely, then I consider his requests but if he is threatening and tantruming, no dice.
This is one of the keys to managing your kid's behaviour. Figure out what the payoff is for a challenging behaviour. Are they using it to get out of doing things? Are they doing it to get a reward? Are they doing it to get attention? Or are they doing it because it feels good somehow (this usually applies to self-stimulation)?
It's important to remember they don't have to get the reward every time. I was told that 1 time in 10 is enough to reinforce the behaviour and that number can go even lower if the reward is particularly desirable (how many of us buy lotto tickets despite never having won a jackpot?).
Once you've figured out the reward, then you have to make sure the behaviour doesn't give them that. If they're yelling to get out of doing homework, they have to do the homework. If they're pinching to get attention from Grandma, she's got to ignore it. The only exception is when the behaviour is self-rewarding, then it's trickier and I've found I have to try and substitute another behaviour which gives the reward but is more socially acceptable.
So when we're looking at tantrums, I have to make sure Nathan doesn't have control over his environment and for Alex, who usually uses tantrums to escape doing things he doesn't want to do, he has to do what has been asked.