Xiola and I made costumes from the Kushiel Saga (by Jacqueline Carey) for Ad Astra this year. They still need tweaking as they were kind of last-minute, but they turned out okay. The dress is silk charmeuse that I dyed myself and cut on the bias (first time doing bias, so it's a bit wonky...agh).
I want to redesign the rose tattoo, as I drew and printed it out on waterslide tattoo paper the day before the con and it's not quite right (I didn't want the same design as on the books).
edit: I got the tattoo paper from here: http://www.beldecal.com/tattoo_paper.cfm
I highly recommend it.