Alison Lee interviewed Donna Kato for this week's Craftcast, and I really liked what Donna said about mistakes:
"When you make a mistake -- or something you perceive as a mistake -- how much worse could it get? You might as well cut it up and put it together some other way. You're risking very little.
"If you don't like what you've done, there's no risk in changing it."
A great philosophy on artistic mistakes... and a great interview overall. Listen to the rest of the podcast here.