For the curving part I did a few rows, then short rows sets (short row portion: knit to two before the last stopping point, turn, slip and twist the yarns, knit to the end. Repeat until only two stitches remain. Turn and work back, picking up the appropriate colour and knitting together with previously slipped stitch. Work two rows plain).

Slipped the first stitch on each side and twisted the yarns to keep the edges interlocked.