“The seed of your next art work lies embedded in the imperfections of your current piece. Such imperfections (or mistakes, if you’re feeling particularly depressed about them today) are your guides — valuable, reliable, objective, non-judgemental guides — to matters you need to reconsider or develop further.”
— David Bayles and Ted Orland, Art and Fear.
Before you destroy a piece, ask if you’re destroying your seed corn. Put it aside, hide it away, save the decision for another day when the emotions from making it are less strong and the results less precious. Sometimes there’ll be something that I like that I then try to do/use again, sometimes it becomes the lower layers in another painting. Sometimes I’ll still hate it and then it gets destroyed, but by then I have other seed.