Jennifer Lopez says new judges on talent shows should "relax and be honest".

The singer-and-actress had a successful period on the American Idol judging panel for two seasons. Jennifer announced she would be quitting the show in July and has since been replaced by songstress Mariah Carey. Idol's rival show The X Factor USA is hoping to win the ratings war after signing up Britney Spears and Demi Lovato. Jennifer's advice for the new wave of judges is to avoid over thinking.

"It's just about being relaxed and being honest, and being yourself…" Jennifer told ET Online. "If you try and think too much about what people might think or what you're saying too much, I think you get lost."

The straight talking star went on to explain her recipe for Idol success. Jennifer put faith in her instincts and tried not to deliberate over contestants too much.

"I always kind of just spoke right from the heart, and how I would want someone to speak to me if I was in that position," Jennifer revealed. "So long as [Mariah] is honest and speaks from the heart and just is herself, I think she'll be fine."

It seems Mariah is already following Jennifer's advice to say what she feels.

The 42-year-old solo star is reportedly frustrated that the rest of the American Idol panel are yet to be confirmed. Sources say Mariah is also annoyed that producers are considering younger female star Nicki Minaj to sit alongside her.

"Mariah hung up the phone when she was told Nicki was the top candidate," a source reported to TMZ. "Mariah was led to believe she would be the only woman on the judge's panel. Choosing Nicki would not only crush that expectation, it would add insult to injury because Nicki [29] is a lot younger than Mariah [42]."