This is my way of dealing with a temper tantrum, post yours so i can have some new ideas!

When the tantrum starts, i would first get down on eyelevel, tell the child that i love them very much, but that im putting them in timeout because theyre (screaming, kicking, throwing things, etc) and then id pick them up and place them in the timeout chair. After that i would say "when youre ready to calm down and talk, let me know." And since theyre not going to calm down right away, theres no reason to keep reexplaining why theyre in timeout. I would leave the room but still listen in, So everytime they tried to get up,i would pick them up and put them in the chair again without saying a word. It might take a hundred times during the first temper tantrum, but after that the child should start to understand that they arent going to win.