for me personally? Taking a deep breath, understanding whats bothering me, being mindful of it and letting it fall to the side. An insanely simple process not as simple of a practice- but that is what it always is, a practice.
It may sound hokey, but I usually pray. It's hard for me to stay angry with someone when I'm speaking to the Divine. The source of the anger and its solutions usually surface shortly thereafter.
I don't process human emotions.
Except for when I have the tuxedo in Minecraft.Fixed.
But for me I am just naturally good at keeping a level head.