Step away from it, when it is ticking in our head like an unexploded bomb that is about to go off, just walk away, physically and/or mentally. When the steam is rising and coming out of our ears, it is not going to get any better by staying involved.
When something has got to us, go and have a tea, a walk around the block, put on some music, find a funny video on YouTube, go and hug someone and let go.
Let go the instant that you feel you are becoming the reaction to the situation that is arising.
Just say ‘WTF’ inside or out loud and move on.