This is one area I've been told I'm too strict on but I really believe in giving bad behaviour as little attention as possible.
With hitting I'll try to grab their hand as they try to hit say "NO" very firm and loud, using a low tone, then just walk away.
Tantrums, so long as they are in a safe place (ie can't be hurt) I'll just walk away. If they aren't in a safe place I'll try to make the place safe, or take them to a safe place and leave them. I refuse to try to ration with a child that is in the stages of a tantrum. Because the tantrum is usually aimed to get attention the child will almost always stop when they are alone and come to find me and then I'll talk with them and explain if they use their words to tell me what they want it will be much easier.
Throwing things, I again use the low, loud "NO" take the thrown item and put it out of reach/away. Ignore the tantrum that is likely to follow by walking away and wait (only moments usually) until the child comes to find me. I'll say I took XZY away because you didn't use it nicely, if you can use it nicely you may have it back. If it gets thrown again then away it goes and doesn't come back that day.
If dinner gets thrown child goes hungry til next meal time - strangely enough they will mostly eat whatever I put on their plates, anything not liked gets left on the plate.
Oh another thing is I work a respect system. I have to show my kids respect for them to learn to give me respect. Therefore I ask them to stop/do/etc. Then if that doesn't get through I tell them to stop/do/etc. Then I enforce by preventing/taking to/etc. Exceptions are if the situation is dangerous, but I will explain to the child after why I was so abrupt.
I make a point of saying please and thankyou to my kids and they in turn say please and thankyou to me.
I also tell them what is going to happen and why.
An example would be
Please sit still and watch the video nicely other wise I will turn it off.
I am coming to turn it off now, because you aren't sitting watching nicely.
I have turned it off because you wouldn't sit and watch the video nicely.
I have mum, nan, aunties, DF's mum, all telling me I'm strict but I have complete strangers comment on well-behaved kids. I simply can't spend 45+ minutes to make a 3 year old sit on a step for 3 minutes, while the other kids are left to do whatever. At the end of the day this works for me and my kids have always got a smile and cuddle for me. I don't have to use the above actions very often because the situations I outlined don't occur very often.
