Tommy Hilfiger is inspired by laidback Californian style.

The fashion designer says the ''carefully studied'' yet scruffy vibe pioneered by the likes of Ashton Kutcher is a source of creativity for him and has influenced his own preppy designs.

He explained: ''It's eclectic, more relaxed than other parts of the world. California is where extreme casual started, where you see Ashton Kutcher and Leonardo Dicaprio unshaven and with old clothes on - almost anti-fashion.

''They wear sweat pants, flip-flops, a beat-up old T-shirt. It's an 'I don't care attitude', but it's very studied. There are also a lot of tattoos in LA - it may be the tattoo capital of the world.''

The iconic designer has successfully managed to cater for both male and female customers, but he admits he struggled to break into womenswear at first and believes it is a common problem among his fellow designers.

He added in an interview with Shortlist's Mode magazine: ''It was the same for Ralph Lauren. A lot of designers have that issue. Its interesting, women such as Stella [McCartney] may not be able to go into menswear easily.

''Donna Karan's men's never really took off. Diane Von Furstenberg can't do men's... A lot of women's design houses can't do men's.''