I loved the emotion coaching side of things from 123.
We talk a lot with the counting and give natural consequences such as "We need to put our shoes on now, or we will miss playgroup. Thats 1. Lets put our shoes on, so we can go to playgroup. 2. When I say 3, we wont be going to playgroup. Put your shoes on please."
I rarely have to go past 2 with my (just turned) 4yo, and Ive found the counting gives her time to think and self correct.
The emotion coaching was along the lines of "You are really cross that I turned the TV off, arent you? Its not time for TV now. We will watch TV after our showers." and then we do 'time in' and cuddle with DD until she has calmed down.