Materials: 1 ball cotton yarn, #7 US needles.
Cast on 45 stitches, or any odd number.
Row 1: Knit across (this is the right side)
Row 2: *K1, Slip 1* repeat between *s across, ending K1.
Row 3: Knit across.
Row 4: K2, *Slip 1, K1* repeat between *s across, ending K2.
Keep working in pattern until piece is square, finishing with a wrong side row.
Cast off in knitting on the right side.
Authors Note: I usually slip the slipped stitches as if to purl. But you can also slip as if to knit, which twists the stitch when you knit it on the next row, making a slightly tighter fabric. I like both ways equally well.
The yarn carried across the back of all the slipped stitches makes little curves across the dishcloth, which look like rows of little waves, hence the name.