How to Stay in Control and Keep Your Cool
1 – Keep Your Voice Calm
Even if you can't stop yourself from tensing up and going red in the face, concentrating on keeping your voice quiet and level can make a bigger difference than you might think. It helps to prevent the situation from escalating, both by limiting how upset the other party/parties are becoming, and by stopping you getting angry at yourself for losing your temper. It also makes step 2 more achievable.
2 – Give Yourself Some Space
If it's even slightly possible, withdraw from the situation and come back to it later. Even if you can only get yourself a minute or two, say by visiting the bathroom or by making up a small but vital errand, it can make all the difference in the world. Breathing and counting to ten is all very well, but if somebody is talking at you while you are trying, or if the other person feels like you are making a show of keeping your temper, then it is only likely to make things worse.
3 – Think Forward
Imagine how things will go if you let yourself fly off the handle, compared to if you manage to keep your cool. When things have run out of control you are less likely to remember the things which are most important to communicate, and more likely to say things which you would rather leave unsaid. While it is relatively easy to come back later and say something you forgot to mention, it's clearly impossible to take back something which you did not mean to say in the first place. Likewise, while you can always come back and lose your temper later, it's something which can't be undone. It also makes people less likely to take in what you're saying.
4 – Empathise
It can be very difficult, but force yourself to consider:
Why are they making such a big deal of this?
What are they trying to achieve?
How do I sound to them?
It's not going to make the friction go away, but so many major arguments happen because one person doesn't realise what the other is trying to say, which leads us neatly on to our last step.
5 – Force Yourself to Listen
If the other person keeps repeating themselves, or seems to not be hearing what you're saying, it may be because they are not putting themselves across clearly, or simply that you haven't been hearing what they've been trying to say. Run the conversation back in your head, and look for anything which you haven't picked up on or acknowledged, even if it was expressed badly or not said outright. Don't be ashamed to admit to a burst of sudden understanding.
Beyond these stages, I have two pieces of advice which may help you in the long run. Firstly, keeping your temper is like using a muscle. The more you do it, the better you get at doing it. Once you start trying consciously and systematically, you will be amazed at how fast you can improve.
Secondly, even if things are changing very slowly and the going is hard, keep trying. Once the people around you start to notice that you are putting the effort in, they will begin to give you more leeway and make more allowances for you. The very act of visibly trying to improve will cause people to want to make it easier for you to do so.