Well Charlotte is not 2 yet but has definitely started testing both mummy and daddy to their limits at times.
I do try to avoid smacking also.
We generally warn 3 times then its off to her bedroom for 2 minutes...
I have found that ignoring does wonders just saying when you ar efinished come find me. they do get it eventually.
I have also found that Charlotte is trying to communicate through her tantrums, i think they are at such a frustrating age you really need to try and distract them away from what is bothering them.
Good luck and its all about trial and error as each shild is completly individual
~ Courts