photo and directions from crochetspot.com:
You may either start by crocheting on the towel using a very small crochet hook or you can sew the finished topper onto your towel when you are finished making it.
Medium Weight Yarn (small amount)
Crochet Hook J (6.00 mm)
Crochet Hook US 7 (1.5 mm) – only if crocheting topper onto towel
Sewing needle and thread – only if sewing topper onto towel
Row 1 (sew topper on towel method): with crochet hook J (6.00 mm), ch 36, sc in second ch from hook and in each ch across: 35 sc
Row 1 (crochet topper on towel method): using US 7 (1.5 mm) crochet hook, 35 sc evenly across top of towel: 35 sc
Row 2: with crochet hook J (6.00 mm), ch 1, turn, sc in each sc across: 35 sc
Row 3: ch 2 (counts as 1 dc now and throughout), turn, (dc in next sc, skip 1 sc) across, 2 dc in last sc: 20 dc
Row 4: ch 2, turn, (dc in next dc, skip 1 dc) across, 2 dc in last dc: 12 dc
Row 5: ch 2, turn, (dc in next dc, skip 1 dc) across, 2 dc in last dc: 8 dc
Row 6 – 17: ch 2, turn, dc in each dc across: 8 dc
Attach yarn to lower corner of towel topper. Sc around side to top to other side of towel topper. Then finish off. Do not sc across bottom of towel topper since towel is (or will be) attached there.
Sew button to towel, aligning it at the lower center of the handle such that the center of the last row can be used as a button hole. If you did not crochet the topper directly onto the towel, use thread and a sewing needle to sew the topper onto the top of the towel.