Kristen Stewart says it's important to laugh at yourself.

The Twilight Saga: Breaking Dawn Part 2 actress has had a tumultuous year after cheating on her boyfriend Robert Pattinson with married director Rupert Sanders but the 22-year-old star - who has recently reconciled with Pattinson - believes you can't take everything too seriously.

"Um, yeah, I mean, if you can't laugh at yourself, there's definitely a problem," the actress said.

"Best not to even approach that aspect. Just think about actually who you are, rather than, you know [what's projected on you]."

Meanwhile, Stewart's Twilight co-star Kellan Lutz revealed he loved working with her on scenes where her character Bella Swan discovers her new strength after becoming a vampire, especially when they had to pretend to arm wrestle.

"I had been very much looking forward to shooting that scene with Kristen," he told Yahoo OMG.

"It's fun watching her play two characters because Bella doesn't have many strengths, she's quite clumsy.

"Seeing Kristen play new Bella is really cool, I had a lot of fun. In real life I would dominate her but in the movie world, I held back."