I usually say "ta for mummy" at the same time I'm taking whatever it is. He doesn't usually seem to mind so much then. A few times just recently DH has just taken whatever from him without saying anything and he's screamed about it. I think that they do understand more than we think and he seems to understand "snatching" or "taking nicely". When he does chuck a tanty I actually do either a gently "shhhh no tantrums" or I completely ignore it and it's over before you know it. So, he gets attention and praise for his good efforts/play etc but nothing for the tanty.

I do use redirection when he keeps opening the same door in the kitchen...lol. I haven't worked out how we can child lock it properly yet, it's right next to the oven and needs to be heat proof. Redirection works sometimes for us.