How do i crochet a shell border on a garter stitch scarf?

I would do a row of single crochet and then follow this pattern. Ch 3 ( counts as first double crochet) 2 dc in same stitch, ch 1, 3 dc in same stitch, ch 1, skip next stitch, do 2 dc in next stitch and repeat from beginning across. (ch 1, skip next dc and do 3 dc, ch 1, 3dc in same stitch, skip next stitch and do 2 dc in next stitch ending with a 2 dc on last stitch of single crochet and finish off or do one more row of the shell stitch.