Too confusing for me to have two projects going at the same time. I can barely keep one straight!
But in keeping with my newest craze, no waste....I do have a basket next to the sewing machine with scraps in it, mostly little triangles left over from the hex's I cut from 5" squares. (I'm obsessed with making hex I Spy quilts right now.)
For leaders/enders, I sew two scraps together. I keep sewing scraps together until I have a roughly 5.5" square and then send that thru my Accuquilt Go and cut the block to a 5" square. Eventually I'll make a quilt using the 5" blocks. Kind of fun because that quilt will have lots of memories of my other projects. It's amazing how fast those 5" squares build up!