EXCLUSIVE: Carrie Underwood Says 'American Idol' Prepared Her for Industry Criticism

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Carrie Underwood reflected with ET about how American Idol impacted her life and helped her prepare for superstardom ahead of Thursday's series finale.

"I think more than anything the critiques were a learning process, because I'm criticized on a daily basis," Underwood told ET's Sophie Schillaci. "It was kind of the beginning of learning what that was going to feel like and how to handle it and getting used it I guess -- kind of creating a thick skin."

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Her thick skin paid off. The 33-year-old country star left the show in 2005 to become one of Idol's most successful alums, winning seven GRAMMYs, 17 Billboard awards, 12 Academy of Country Music awards and 9 American Music awards.

Underwood took the stage at the finale belting out her duet with Idol judge Keith Urban, "Stop Draggin' My Heart Around," showing off her toned legs in a sparkly tube top and short skirt.

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As Idol passes the torch on to other singing competition shows, Underwood gave advice to those other hopefuls wanting to follow in her footsteps through reality TV.

"Learn everything you can," Underwood told ET. "Be nice to everybody because these people that work on the show, I see them everywhere -- at every award show, at everything everywhere. Be nice and learn because it's an opportunity. You got to soak it all up so you can try to make a career after the show is over."

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Aside from music, Underwood has also proven herself to be talented in the fashion department. She stunned on the Idol finale carpet in a sheer Yanina Couture gown on Thursday, and she told us the process of picking it out was fairly simple.

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"I put it on and I was like, 'Yep!'" Underwood said. "It's just different."