Feather and Fan

It's taking me about an hour to do one four row repeat on my shawl that was supposed to be just a guage swatch. I was at Acorn Street on Monday trying to pick up a needle for my roomate (they didn't have it) and found some accent colors that look lovely with the grey that the majority of the shawl will be made of, a green and a purple, so I'm thinking of putting a double border on one of the long (straight) edges of the shawl. I dread the thought of figuring out how to border feather and fan's wavy edge, so I'm not going to.
If anyone has any suggestions that could allow me to border the wiggly edges, I'd love to hear them... Is there anybody out there?