The way I work, I will deliberately make a couple extra scrappy blocks per project because sometimes one just doesn't play well with the others. The term I hear most used is "orphan" blocks. Unfortunately, dealing with orphans is not one of my super powers, but many people on the board do wonderful things. From putting them together as samplers, to making placements or other projects, often people who make smaller donation projects actively want the orphans and I give them when I can.