I have been practicing stopping my reactions recently after a realisation that I can actually stop a reaction just as quickly as the heat of it rises within me.
What I have noticed about reactions is that as you are in it you can feel that something is not right, you know that you may regret what you're doing or saying or that you may have to face some unpleasant consequences in the aftermath of your outburst (or whatever). I actually tested this point for myself, I would slow down within my reaction and acknowledge that knowing within me that I was in the midst of making a mistake but still allow the reaction to continue. Afterwards I would assess whether that feeling was accurate or not. It was, every time.
The reason that we usually use to not stop a reaction even when we know we should is "I am right" - whatever I'm thinking or saying is right and everyone else is wrong. This experience of righteousness can often make stopping the reaction quite difficult when you are not willing to accept that you may be wrong regarding any or all things in your life. For me, once I fully accepted in every moment that I may be wrong about anything and everything I believe to be true and once I realised that whenever I believe I am right with conviction I am probably wrong - it became easier for me to slow down within a reaction and start assessing myself and the situation I'm in more objectively.
Part of the change is especially regarding word choice - whenever I am experiencing even a small reaction I remind myself to stop what I am saying and take a step back so that I can reassess the potential effects of my words. Doing this small thing alone has prevented many potential conflicts or other unpleasant experiences within me and others. Another way I can describe this point is to not say or do ANYTHING in the heat of the moment - whenever there is any heat or movement within you you know you need to stop and take a step back.
It's strange, it's like a part of us wants to react and allow a full on emotional explosion, like we are entitled to rain down chaos and destruction on the people and the world around us. It's like we stop caring in that moment and are absolutely consumed by the experience that has taken over. The key to realise is that you are never truly absolutely consumed - the point of self responsibility always exists. This means that you always have the ability to stop the reaction, the point that is often lacking is the willingness to stop it in that moment. We so often will go full on bonkers and only afterwards realise the damage we have done. That is where the remorse comes rushing in.
I have trained myself to listen to that feeling of uneasiness when I am in a reaction. This does not mean that I catch it in time every single time - it is a process that takes time and practice. What I have also implemented for myself is to repair any damage I do as soon as possible - I make sure that I let the affected people know that I realise that my behaviour and/or words were not acceptable. Within this application that I have been walking I have found that I am much more satisfied with how I handle situations and myself, I am not left with an icky feeling inside me of "I could have done better" or "I could have avoided all of this".
So now when I react I often am able to stop myself before I say or do anything I may regret. As I have been doing this it has become easier - I have also noticed another interesting side effect: I am more patient and supportive with others when they are in a reaction. I have found that I am more able to direct and support people out of their reactions. The most interesting realisation I have has is probably that most reactions stem simply from a lack of understanding, most often a lack of investigating and understanding the entirety of a situation and each person's position within it. As I push myself to look at what other people around me are going through and why I find that this point of understanding is also becoming easier.