Try looking in a mirror when you're in a state - mad, crying, stressed, etc
Seeing how you look when you're upset shows you what everyone else sees. "Wow, I look like that? That's ugly." or "Hey, I look good when I'm crying, my eyes are greener!" Either way, you change your expression.
It also takes your mind off your problem for at least a few minutes and when you think about it again, you have settled down some and can more readily deal with it.
I haven't tried this on my children, but I think I might. Although with them it would probably backfire.