Lay wool fabric on cutting mat, and cut to desired length using ruler and rotary cutter. Repeat with cotton fabric.
Place right sides together, cotton side on top. (Sewing on cotton, rather than wool, minimizes slipping.) Place pins at each end and at regular intervals in between.
Machine-stitch all 4 seams, leaving a 1/2-inch opening in middle of one short end.
Clip corners at a 45-degree angle (be sure not to cut stitching) to ensure they are sharp when you turn fabric right side out.
Turn fabric right side out, and gently press with an iron until seams are crisp.
Slip-stitch the open end closed.
Lightweight wool or wool-blend fabric
Clear quilting ruler
Fabric rotary cutter
Lightweight cotton print fabric
One side is soft, cozy wool; the other is light, cheerful cotton. To speed assembly and personalize each piece, you can use one wool fabric and pair it with multiple matching cottons. The best part is that one size fits all. Cut all pieces before you start sewing.