When I make bread, if I don't get a little dough on my hands when I am shaping the loaf, I pinch off a very small amount. I scrape up the flour from the surface where I work the bread, put it in a small dish with a lid with the dough from my hands or what I pinched off and add some water. I leave this out for a day, then refrigerate. It essentially becomes a poolish. Not really a starter, nor a sourdough, but adding this to the next batch of bread increases the complexity of the flavor of the bread. And saves the flour from the work surface.