As many of you, I'm a great starter but not a great finisher of projects. I have a large pizza box full of orphan blocks, too. But we have a long winter here in Vermont, so on the snowiest days I get out my orphans and make table runners and table toppers. These might have been bigger quilts at the beginning. Anyway, finishing these little projects helps me feel like I'm actually accomplishing something. And the backs are perfect for that nice "I can't cut it" fabrics.
But now that it's summer, I find myself starting a few new projects, pecking away slowly at older ones, and not doing as much quilting as in winter. I am kind to myself and sit and read for a whole afternoon if I feel like it. My best advice: lose the guilt, enjoy the hobby when the mood arises!