Mr W is very intense.
We remind him to "use his words" and he will get more of what he wants.
We've had a lot of success with acting out his tantrums using his stuffed toys and dinosaurs as well to show him how silly it is.
He is getting better and better with his meltdowns limited to less than one a day.
We also use the empathy track. Back when he was less than a year old, he had a horrible melt down while I was on the freeway. He had already agreed to go with me to the bookstore but changed his mind. He could not speak well then but understood me when I talked about how his tantrums hurt people's feelings. I had taken the day off to spend with him and all the stuff I'd planned he did not want to do and he was hurting my feelings. it worked pretty good.