I created a seed-stitch edging for the neckline of the shawl because I’m not a fan of the rolling edge.

Here’s how I did it.

Work the short rows til you get to the point where there are 3 unworked stitches at each edge, having finished a wrong side row. Keep work to the wrong side.

Row 1 (WS): p1, k1, p1. Cast on two new stitches.
Row 2 (RS): p1, k1, p2 together (this will consume one stitch of the shawl). Turn.
Repeat these rows until all stitches except the last stitch are consumed. Bind off in pattern as follows:

p1, k1 (pass stitch over), p2 tog (pass stitch over). Cut yarn, and pull yarn through the final loop.