For American Idol newcomer Jennifer Lopez, the perfect pick-me-up during her first full day of judging was a fresh batch of eager contestants.

"It was a long day, but it wasn't tiring," Lopez, 41, said of her first day on the job in Jersey City, N.J. "I was energized by all of [the contestants'] spirits when they came in here – so hopeful about what could happen and how it could be. And it's exciting."

As the first round of auditions kicked off on Tuesday, the singer-dancer-actress is embracing her new role, describing her style as a mix between "tough, easy and fair."

And she's not letting anyone off the hook.

"I really want to put them through the wringer in the sense that I don't want to let anybody who's really great go ... because they're nervous or whatever and not get to see what they could've been," she said. "We worked with them a little more than maybe you’ve seen in the past. We give them more of a chance.”

Steven Tyler, the other panel newcomer, had advice for future Idol hopefuls: "Don't get mad at what we say – get better."

Veteran judge Randy Jackson also had some words of wisdom about rocking an interesting look: "Whatever you do, make it hot."

And with the show returning to Fox in January, host Ryan Seacrest was psyched about the three different styles the judges bring to the table.

"The chemistry is fantastic between these three," he said. "You know, they're having a good time."