Tie one end of the embroidery floss to the washer; trim down the excess. Start wrapping the floss around the washer, threading through the center. Keep the loops snugly against one another, unless you like the look of shiny metal peeping through your floss. Continue wrapping until washer is completely covered. Loop tail through the center and knot to finish the now-fabulous pendant.
(For larger washers, try using yarn. It's all fuzzy and fun-looking!)