Honestly, I would just call in a long ribbon, and being a Sheryl Nome cosplayer, I see stuff like that all the time. Your particular ribbon I would make as follows: make a pattern for it by cutting it with one straight side while the other like a long oval with the bottom end tapering into a point and the top just a straight line as well. (<~ I hope it makes sense, it's very hard to put the pattern into words xD If cos.com had a draw feature, it'd be so much easier). Then I would cut two pieces of fabric to sew together and to make it pose-able and bent like the photo, I would sew a very small channel at the edges of the ribbon to insert craft wire. I don't know how you plan on attaching it, but I would then sew and press the rest of the ribbon, leaving a small opening near the top of the ribbon to which you'll attach a ruffle at the peak of it.
Hope that somewhat helps, and good luck. If something's not clear, let me know and I'll try to make it better understood.