Claudia Schiffer doesn't take her make-up off before she goes to bed.
The 47-year-old supermodel insists it is fine to break one of the most well-known beauty rules when wearing an "amazing" smoky eye because it looks even better in the morning.
Asked her best beauty tip, she said: "Something really not allowed, sleeping with your make-up on.
"If you have amazing black smoky eyes and then you sleep on them, the next morning - amazing."
The German beauty credits Karl Lagerfeld as one of the designers who changed her life, and it was advice from him ahead of her first catwalk show that has stuck with her throughout her career.
Asked the best career advice she'd been given, she explained in an interview with Harper's Bazaar online: "Karl Lagerfeld, he actually said, 'Just be yourself'.
"He asked me to do my first fashion show for him and I didn't want to do them because I was very shy.
"He said, 'Just walk out there and do what you want to do, walk out like you'd walk on the street' and that sort of stuck."
And Claudia admits her first-ever fashion show is still her favourite because it was so exciting, even though she was sick with nerves.
Asked which was her favourite, she said: "Maybe the first one, that was the most exciting, I couldn't sleep all night long. I actually had a fever the morning of because I thought 'I can't do this', but it was a great success so it turned out all good."
The German beauty believes the fashion industry has changed massively from her 90s hey day to now.
She explained: "It's much faster paced, more collections and everything is changing all the time to a speed a thousand times quicker."
And for any aspiring models, Claudia believes the key to success is being open to anything.
Sharing her tips, she said: "Being available to do whatever the vision is of the photographer. 'No' doesn't really work very well, unless it's some indecent proposal, that would be OK, but be open to absolutely anything to get a great picture."