Make a foundation chain of the required length, or work row 1 directly into the item to be trimmed with right side facing.
(multiple of 8 stitches + 1)
Row 1: 1 ch, 1 sc in each st or position to end, turn.
Row 2: 3 ch, *(1 ch, skip 1 st, 1 dc in next st) 3 times, 2 dc, rep from * to end, turn.
Row 3: As row 1. Fasten off.
ABBREVIATIONS / REFERENCES Click for explanation and illustration
ch(s) = chain(s)
sc = single crochet
dc = double crochet
st = stitch