I use the white-white muslin as the background to miniature (3"x5") service star flags, which I sell to raise funds for local veterans programs. People mount them onto car and home windows.
I am making 4- and 9-patch blocks with white/cream muslin alternating with my colored scraps.
Foundations for crazy quilt blocks, string quilt blocks, braid columns and the like.
Backing for doll quilts for my granddaughters
Lining for tote bags