When I worked with sterling silver creating art jewelry pieces, I made my own bezels for pendants, rings, and earrings. When I wanted to add color or a design, I worked with epoxy resin.
Well when I started out I would put the pieces filled with the epoxy in my toaster over so they would cure faster, and on a few occasions I left them in there to long and the epoxy started to bubble, creating creators in my design. I would be so pissed off that I wasted all that material and that the piece was not perfect anymore.
Well in the end I showed it to a few people who thought it was really cool and it turned out to be a technique that was uniquely mine and I used it often when I was creating with color.
It's hard to let go of the idea that everything has to be perfect. What dose not look good to us, may look good to someone else. We have to give our mistakes a chance, they could inspire a new idea, start a new technique, or even be the best mistake ever.
Never say "oops." Always say, "Ah, interesting."
What mistake have you made that turned out to be a creative discovery?