When I start a small project, like a lap quilt, i generally see it right through, however, a year ago I had a major physical problem and was unable to finish anything, so I built up a pile of 21 tops (flimsies) intended to be charity quilts for kids in out of home placement. Yesterday, I handed over the last of them, so I am down to about 20 UFOs, about half in the final piecing stages. I don't have enough room to store things.
Lots of times I try out a block that does not quite work for what I want or I do not like enough to go farther. I have a bin for those. When I want to make a scrappy quilt, I often center individual large blocks of those. I have also made several purses from these abortions. The effects can be quite dramatic.