Carpenters have a saying: "Measure twice, cut once."
In my struggles with my own temper, which can get pretty hot, I've found a lot of use in a permutation I've made of the above quote: "Think twice, speak once." When I hear or see or experience something that upsets me, I'm finding it useful to stop and think about my response rather than speaking or acting out of impulse.
It's an ongoing thing.