However, you could also do a rolled hem using your sewing machine. There's an excellent tutorial here for how to use your sewing machine and rolled hem foot to accomplish the same thing. You should definitely check it out. http://sewingmel.com/wordpress/index.php/2011/03/rolled-hems-on-a-sewing-machine/
While you are there, I recommend exploring the rest of her work too as she is extremely talented! Thanks, Mel :)
After finishing the curved edge, sew some gathering stitches on the long, straight edge. Pull up the gathering stitches until the bottom of your frill is even with the mark on your front pattern piece and the top is even with the neckline of the shirt.
Baste both frills in place.
Okay, now, take your button bands and sew the interfaced edge to the opening edges of your fronts, right sides together with the frills sandwiched between the shirt fronts and the button bands.
Flip your button band out and press.
Looking good, right?! I'm afraid that is all for tonight--Allie's birthday is tomorrow, and we have a cookie cake to decorate!