Get enough sleep. This is the best piece of advice I have. I had two incredibly cranky children, one inclined to cry the other to pout, yesterday evening. This morning? Cheery! Able to follow instructions without angst! Cooperative! It is brilliant.
Sadly, I’m having a little trouble following my own advice. It is hard to keep sleeping when you dream that someone is sticking a finger in your eyeball preparatory to pulling the eye out. My unconscious doesn’t like me very much sometimes. Maybe it doesn’t know that I’ll stop being cranky if it lets me sleep…