If I can, I take an afternoon nap or go to bed early. I let my subconscious do all the heavy lifting compartmentalizing what happened and I generally wake up a lot less stressed. If I can't lay down of sleep, I'll try and center myself. Saying the Litany Against Fear is one way. Mindfulness of Breathing meditations are another good way for me. I also know the mantra of a Buddha associated with fearlessness and calm in the face of danger. All work well for me.

What is the nicest gesture you've ever received from someone? (Friends, Family, even a Stranger)