I had another look at the Lacy Lace Ups. I think they cast on for and worked the ruffle, decreased, worked a picot hem, continued on with the sock. Maybe. Maybe not. To reverse for toe up, I think you'd work a picot hem then increase for the ruffle.
Cheating is an option. . . . Cheaters never win and winners never cheat, but smart knitters who want to retain an iota of sanity do, cheerfully. ~~Kory Stamper