Laughter

Goodness knows I've done enough stupid things in my life. I'd post them here, but it would take days. Plus the fact that I don't like making mistakes so I try to forget them.
Seriously, though, sometimes the best ways to ease a situation is to laugh at your mistakes. Of course this is only guaranteed to work if you're the first person to laugh; being laughed at by others doesn't really make anyone feel good, not unless you were intentionally trying to be funny. (Like the time I was lecturing a friend on why they should watch where they're going so they don't bump into anything, and I was bumping into trees and fire hydrants and mailboxes and street signs and any other inanimate object that happened to be remotely in my vicinity, excluding things in the street. Like cars.)
So laughing at things you do intentionally is fun and relatively easy to do, since they were done for a laugh anyway. It's the stupid things that were done seriously that are the hardest to laugh at -- at least, the hardest for the person who did them to laugh at. But sometimes laughing at yourself is the best way to actually recover from a mistake. It allows you to admit that you made a mistake, and it lets you move on (and find a way to fix it, if necessary).
And laughter is good for you. Make light of your mistakes, that way no one can hold them against you. Laugh at your mistake, appologize, and correct it (assuming you know how). Just don't be the first to laugh at someone else's mistakes, let them laugh first. Because laughing at other people's mistakes is a good way to get a punch in the nose.