Etsy shop owner Denise DuBois (House on the Hill Quilts) loves making pillows from her old sweaters and her stash of fabric remnants and notions. “Cotton sweaters work the best for me,” she says. “They don’t stretch as much as polyester or wool and, best of all, they won’t pill!” Cable-knit sweaters in particular make smart-looking contemporary designs. Here, DuBois machine-quilted a panel cut from an old sweater to a piece of cotton batting and some fabric backing so that the pillow retains...