Whether it's coaxing Crystal Bowersox to slip on a pair of high heels or convincing teen Katie Stevens that she's already got her own "pop star" look, "American Idol" women's stylist Soyon An is a big believer in keeping her season 9 clients fashionably true to themselves.

"If they are not comfortable, if they don't feel it, it will affect their performance," An tells StyleList. "So what I try to do is refine their style. I am looking for things they love, that they feel good in, and most of all, that flatter them."

An, who also serves as resident costumer on Fox's "So You Think You Can Dance," has toured with previous "American Idol" stars and styled the female contestants since season 7. Miles Siggins is her counterpart for the show's male contestants.

Along the way, An has slipped on a few extra layers of protection against the sometimes blunt critiques of her wardrobe choices from the "Idol" judges.

"At first when they started to get on an outfit I was like, 'What's going on? They're talking about the clothes?' If it comes from Simon [Cowell], I just kind of expect it now," says An. "But I do listen. I am helping the contestants develop their look and image. So what the judges say is important; it's why they are there."

If a contestant is dead set against heels or arm-baring dresses ("I've dealt with a lot of quirks," An says), she must make it work. Her weekly allotment of $400 per contestant has made her a master of "high-low" dressing.

To create a pop-star vibe on a budget, An might build a look around a pair of Black Orchid or Rich & Skinny skinny jeans, an asymmetrical Hot Topic T-shirt, and piles of costume jewelry from Los Angeles designer Tarina Tarantino or Forever 21 offshoot For Love 21.

If she needs a glam dress, she often turns to Bebe. In L.A., she's a big fan of vintage stores and one-of-a-kind boutiques along Melrose. For cute shoes on a dime, An often hits Aldo.

Since female singers have been the first to go in this season's Top 12, An is down to dressing Stevens, Bowersox, and Siobhan Magnus. "I have time to give them lots of TLC," says An. "Last week, I had a top airbrushed for Siobhan. It's the kind of thing I wouldn't have time to do if there were more female contestants."

Here, An tells StyleList her vision for each of the remaining "Idol" ladies.

Crystal Bowersox: Last week, An persuaded the dreadlocked, Boho Bowersox to slip on BCBG heels and a dress. "She was on the fence about the heels and spent the whole weekend thinking about it," says An. "Once we decided to go for it, we had to go looking for the right shoes.

"She was playing at the piano for the first time too, and comfort was key. If we had changed her up too much, she would have felt awkward." As for Bowersox's overall look, think eclectic. "The dress I did for her last week was off the rack, but I reworked it to make it more Crystal," An says. "I did an open back, and we changed the silhouette. Then we threw on leggings to make it even more Crystal."

Siobhan Magnus: "I call her my 'versus' girl," An says, meaning that Magnus is a study in wardrobe contradictions. She is, after all, the kind of girl who will wear lace-up work boots with an ultrafeminine dress. "We see eye to eye on the things she likes," says An. "I call her style 'Boy Meets Girl' or 'Rocker Meets Glam.'

"I am not sure she could ever be relegated to a single look, because she likes a mixed template so much." An says Magnus has a "killer body" that would be amazing in a glam gown, but adds that "even if we did something old Hollywood on her, something would have to be edgy. We would have to play with her hair accessories or something to stay true to her."

Katie Stevens: "She's very open and trusting," An says of Stevens, who has embraced the opportunity to try out new clothes, even sitting down at the computer with An to show her some celebrity styles that she loves. An paid no attention to the specific stars, saying, "I'm terrible with names, but the point I am trying to get across to her is, 'Never mind those people -- I want you to be the trendsetter!' I want people saying, 'I want that Katie Stevens vibe.'"

The look An is going for is "less sweet and more rock with a twist of pop," she says. Since Stevens is 17, "it is important to keep her look young and real," explains An, who enhances the brunette's hair and olive skin tone with bright colors. "She looks great in hot pinks, bright blues." An also loves to pile jewelry on Stevens: "I can put, like, 15 bangles from Forever 21 on her arm and it looks great."

Stay tuned for our "American Idol" men's style secrets.

In the meantime, get "Dancing With the Stars" fashion scoop from the costumer himself.