With the tacky but coveted mirror ball trophy on the line, the three couples in the "Dancing with the Stars" finale needed to sparkle just as bright.

Kirstie Alley flaunted her toned curves in a body-hugging unitard, Hines Ward transformed from football's Silent Assassin to a bedazzled drum major and Chelsea Kane was literally live-wired for the season 12 finale.

The show's Emmy-winning costume designer, Randall Christensen, executed the celebrities' most personal visions for their make-it or break-it dances.

Here, Christensen takes us behind-the-seams to dish on the finale looks:

Photos: Adam Taylor, ABC


Hines Ward and Kym Johnson: Fred Astaire and Ginger Rogers were the inspiration for the couples' quickstep look, which included a classic top hat, tuxedo and tails for the Pittsburgh Steelers pro. Johnson's sublime gown featured white sheer mesh encrusted with 12,000 crystals and hand-dyed-and-cut guipure lace appliqué work. For a contemporary twist, its sheer skirt was fringed with horsehair braid.

For their freestyle performance, Ward lived out his marching band fantasy in custom-made drum major regalia. Christensen's team used velcro and gussets at the armpits to give Ward tear-away sleeves to crank up his dance moves. Meanwhile, custom costumes for the musicians that joined the couple on stage were ordered from Texas in Steelers' black and gold and arrived "in the nick of time." Johnson's majorette "boots" were actually spandex spats slipped over her Latin dance shoes for ease of movement. Her gold fringe minidress was a sexy take on the majorette/cheerleader look.

Photos: Adam Taylor, ABC


Chelsea Kane and Mark Ballas: Since she first slipped on Christensen's fringe party in the U.S.A. pants during Patriot's Week, the actress has been a fan and requested the style for her samba. For more fun, Christensen added fringe under a row of thousands of hand-beaded crystals on top. "It was tons of work, but hey it's the finale," he says. "And I have to admit it. No one wears fringe pants better than Chelsea."

For their "Tron"-themed freestyle, the couple deviated from classic ballroom style and requested costumes that didn't exactly match. Kane wore a turquoise bra-top and Ballas a lime-bedazzled suit. "That surprised be a bit since Mark's suit was such a bright color, but I obliged them because I want to empower each couple and they should have what they want for this very important routine." The battery operated shoes and gloves were installed by singer Chris Brown's lighting team and "it was a wiring nightmare with all the lifts and choreography." While the drama was spectacular the special effects were a fashion challenge: Kane said after the broadcast that one of the battery packs slipped off after her first big move and was dangling during her performance.

Photos: Adam Taylor, ABC


Kirstie Alley and Maksim Chmerkovskiy: The actress wore a minidress featuring Carnivale hues of bright orange, yellow and lime green accented with crystal infused fringe for her sexy, sassy samba.

For her freestyle to Pink's "Perfect," Christensen deliberately outfitted Alley in a monk-brown dress, which was torn off to reveal a formfitting black unitard that showed off the slimmed-down figure of the actress who has lost 60-plus pounds in the ballroom. The designer's fashion message? "Hello world, here is the new Kirstie, hot and fabulous."

"Kirstie has been transforming right before our eyes and what an eye-popping end to such a glorious journey. And that was all Kirstie with just a bodysuit and her magnificently toned body."

For more "Dancing with the Stars" style scoop, read last week's costume recap.