Share your crafting fails here! 
I've just been undoing some crochet rounss to redo them so that the squares will lie flat(ter) when made up into a blanket.
Despite unravelling several hours' work, I see it as a step in the right direction and I'm getting a buzz from working out a solution to the problem.
What crafty work in progress have you learned something from, did you manage a redo (evwn from acratch) or are you still scratching your head over a solution?