As I work on various projects like the Speedy Chicken quilt, I cut 1.5 inch hunks...just enough for these spools. These are 3.5 inches unfinished, 3 inches finished. I cut two 3.5 inch lengths of background fabrics. And I cut one 3.5 inch length and four 1.5 inch squares for each spool. Then as I sew on other projects, I slip these in. I'm not methodical enough to call them leaders and enders...they are more like...oh yeah these, let's make a pile.
I have tried to stay away from bright colors for the spools, but that gets a bit hard given most of the quilts I work on are quite bright. Happily, my quilt guild has a free fabric table at each meeting. I try to bring more fabric than I take...but this is where I find quiet scrap bits. In the photo above, ten of the spools came from the free scraps.