I save my scraps for string or scrappy quilts. I did make crumbs once or twice but don't care to do it again for several reasons: I hate to work with really small pieces of fabrics,
you use lots of thread (I used spools and bobbins that had only a little thread on them) and you need to buy fabric for the sashing which sort of defeats the purpose of using scraps.
I like the idea of saving little scraps, trimmings, small pieces of thread and batting in a fabric pillowcase that will be used as a doggie or cat mat/pillow. May in Jersey