Supermodel Claudia Schiffer says being happy is the key to looking good.

The mother-of-two - who will turn 40 next year - says she takes care of her appearance but believes the main reason she still looks great is because she puts her happiness first.

"It is all commonsense. I try to drink lots of water. And when it comes to having beauty treatments I try to choose things that make me feel better about myself," Schiffer says.

"Doing things for yourself is important when you're a busy mother. So whether I have a massage or reflexology or a long, hot bath, it's about taking time to look after yourself and be happy. That for me is the secret."

Schiffer - who is married to film producer Matthew Vaughn - says she feels better now she is approaching 40, than she did in her 20s.

"My friends are my age and we all look the same so we don't think, 'Ooh, I am getting older.'

"I feel very confident in myself and I feel better at my age today than I did when I was 20 or 30.

"So if someone said they had a magic wand and could make me 20 again I wouldn't want it.