I casted on 60 stitches, placing a stitch marker after the 30th stitch. Then I knitted one row.

The remaining rows were done as follows: knit to two stitches before the stitch marker, K2Tog, slip marker, knit to end of row.

Knit the final two stitches together, cut the yarn, then undo the final loop to make a soft corner.

Weave in the ends.