Maybe I’m in a rut, knitting multiples of patterns. But this is such a good one. Take two colorways of Noro Silk Garden. The more different from one another the better. Cast on an odd number of stitches for the width you want, worked up in knit 1, purl 1 rib. I usually cast on 45 stitches in Silk Garden, on size 7 needles. Alternate the colorways, every two rows. That is, knit 2 rows from one skein and then knit two rows from the other. Keep up the knit 1, purl 1 ribbing until you use up the yarn. It’s that easy.
Jared Flood has published a free pattern here, while disclaiming that he really invented it. If you’re interested in giving it a try, check his pattern for a handy tip so that the edges come out nice and neat. It works well.