Black Swan was incredible. I highly recommend seeing it splashed across an enormous screen, and as RoRo pointed out, it's like being in the audience at the Ballet that unfolds throughout the story. With costumes designed by Amy Westcott, and the ballet tutus by Rodarte (the label created by the Mulleavy sisters), Black Swan is also a feast for the eyes. Here are some interview excerpts about the design inspirations...
“If I had imagined a dream film, this is definitely the one to sign us up for,” Laura said. “The big question was, how can you create a whole Swan Lake ballet to coincide with the modern set of this film?” But that wasn’t the only big question—the other was one few designers encounter: How can you make clothes that are ballet-friendly? “It was very technical, because everyone had to be able to dance,” Kate added. “For example, the crown—the demon Rothbart has a metal crown that’s made with horns, and the Black Swan has a metal crown in chrome. That was a big debate, whether they could wear them as dancers.”
But necessity was the mother of invention. The crowns made it into the film, where they’re chillingly dramatic in its final scenes—but chrome they’re not. The Mulleavys ended up making the Black Swan crown out of lightweight copper, which they then burned to achieve their desired effect. “The crown is so coveted because it is symbolic of getting the role of the Swan Queen in Swan Lake—it’s part of this whole thing of getting the role. When it was time to do the Black Swan, that more intensely had to be linked to this demonic, menacing idea, [so] using metal became more important,” said Laura (on set with Portman, below). “Technically it was almost impossible, but we made it work.”
As to be expected, Rodarte sought inspiration in some bizarre places while designing the ballet costumes for Black Swan. "We imagined him like a mechanical bird — his breast is even padded out like a bird," Laura Mulleavy said of the costume for Prince Siegfried, which features distressed velvet with a floral embroidered cheesecloth overlay. "It looks like a spider web's taken over him ... He's like a demon." Meanwhile, Odette's costume involves a flat, pancake-shaped tutu made of white angora wool, which looks like "tree branches growing [on the skirt]," she described. Which is not very sexy, but definitely not boring either. 
"We had an affinity for the subject matter," noted Kate Mulleavy. "We had never done a film. ... This would be a dream job in terms of just getting to make tutus. But, then we had, I think, something that allowed us to add to access the psychology of the film in a different way, which was understanding the darker nature and more of the twisted kind of underbelly of that world."
