Avoiding things/situations/tasks that have shown themselves in the past to tend towards being frustrating for you. It's probably an obvious one, but for myself, until I consciously did this, I'd stubbornly try to do it anyway(!) Which inevitably caused me to launch.

And distraction. Maybe watching funny shows or movies. It can help draw you out of your head (if your thoughts are tending to fuel the agitation). And it doesn't require interaction. Interaction is so hard when agitated. Well, positive interaction anyway...