For the bows and skirt I used polyester poplin, or "poly poplin." It's cheap and really easy to work with, and comes in just about every color imaginable! For the bows you're also gonna want to use some kind of interfacing to make sure they stay extra stiff and poofy ~ I always use decor-bond from Joann Fabrics, it's a really heavy-duty interfacing meant for home decor projects, but it works wonderfully Good luck with your cosplay!! <3
Great cosplayer indeed!!!