Adding ruffles

I’m making a basic garter stitch scarf & would like to add something to it. It’s just kind of plain looking. I thought a little ruffle or decorative edge on either end would look nice. I know I probably just pick up stitches and maybe do an increase. But how much?
Yes, I’m a newbie… So any suggestions are welcomed.
Or if there is something else equally as simple…
No fringe please.

You can pick up stitches with an increase in each one, or just pick them up and increase in each st on the next row.