The moment I get emotionally engaged with my near 3 yr old the worse it gets.
So, what do I do? I try and remain as calm, cool and collected as I can, v difficult at times.
It is on my mind a lot that I am the role model, so when I get fed up I tell him it's his behaviour I don't like (not him)I try and talk about his feelings, give them labels to help him.
3-4 yrs is all about learning about emotions, so giving them labels and recognizing to my child when he is angry, sad whatever I think is important.
I praise whenever I can, e.g for helpfullness, kindness to the cat etc and am never scared of allowing time for the tantrum to end. He has the problem, he needs to deal with it, and like another post says sometimes words from me are useless. I just make sure we talk about it afterwards and how he feels.
End of each day at bedtime I go over what happened in the day (even with c**p days I don't focus on the tantrums too much, but he likes hearing about the day, and tell him I love him.)
I know it's hard, but think it will be worse as a teenager!