My 2 boys have very opposite personalities. My first has always been very easy-going, compassionate, somewhat cautious/anxious, and not an aggressive bone in his body. My second is more independent, strong-willed, and fiery. Those are not bad attributes at all; quite the contrary, actually. Both boys' personalities are wonderful in their own ways. They also require different things.
My fiery one is more aggressive and is coming out of a hitting phase. Starting right before he turned 3, for a good 4 or 5 months, that boy hit someone 10 times an hour, usually his older brother, who always shied away from confrontation. I tried what felt like 50 different "techniques" to get him to not hit, and I don't think any of them "worked" so much as he just outgrew that phase. He's 3-1/2 now and he doesn't hit nearly as often as he used to, but his temper is still quick.
I happened across this free printable online for my kids to color one day. We talked about it, and I hung it on the refrigerator as a reminder. I hadn't planned on this becoming a "thing" at our house, but it has evolved into a very helpful tool for all of us.
Red - Stop
Yellow - Calm Down
Green - Go
For the first few weeks this was hanging on the refrigerator, I would only occasionally refer to it when someone got angry. "What should we do first? What does the red light mean?" One would chime in, "It means stop!!"
They totally got this little stoplight, so, I ran with it. We have talked extensively about each step on this stoplight. I've given them tools to use at each step.
Red light! I say this when I see one of the kids (or both) getting hot under the collar. I've given them several options to do during red light, including walk away, sit down, and take deep breaths. If someone is very angry and I see that he will need help red lighting, I step in and offer my assistance. "Let's take a walk together" or "Put up your moose antlers and let's take 3 deep breaths."
Yellow light! Next is calm down time. Again, I've taught them several different ways they can calm down. Draw a picture, look through a book, pop balloons, shake the calm down jar, etc.This is not a go-sit-in-a-chair-for-x-amount-of-time-and-calm-yourself-down kinda thing at all. And again, if someone needs help, I offer it. "Would you like to draw me a picture?" or "Would a hug help you?"
Green light! Go! I usually don't even have to say this one as once the child is calmed down and we've discussed the issue if it needed discussed, then he merrily goes about his way.
This is a really good tool to use in conjunction with teaching emotional intelligence. Used on its own and without offering the child assistance in the steps or teaching alternatives, it may not be very useful, and certainly this could be spun into something punitive, but that is not how we roll here. When I give these verbal cues, it is a loving reminder to take a breather and collect yourself, and its not just for the kids. I've told them to feel free to say, "Red light, Mom!" if I start to lose my cool. We can all use the reminder sometimes.