Philip Treacy thinks hats should be worn with ''simple'' outfits.

The acclaimed milliner has styled the likes of Sarah Jessica Parker, Naomi Campbell and Britain's Duchess Catherine in his famous headpieces, and insists the accessories are best teamed with uncomplicated dresses.

He told Vogue UK: ''Shopping can be a nightmare. First finding something to wear and then finding something to go with it, it's so difficult when there's so much choice.

''It can feel like entering a battle ground, so my advice is to always choose something simpler - an expressive outfit, plus a hat, can be frightening.''

As for finding the right hat, Philip advises it is often a case of ''trial and error'' and dependent on the wearer's own personal style, as well as the function they are attending.

He explained: ''The success of a hat definitely lies with balancing the personality of the wearer with the type of occasion. Don't listen to those rules about face shape.

''Try on 100 different hats if you can, until you find the one that suits you best. It's a trial and error thing.''

The hat designer warns, however, that popular hair accessory, the fascinator, is ''lazy'' and couldn't hold his contempt for the hairpieces.

He said: ''I don't have a huge issue with them, but they're the lazy option. You don't have to be lazy!''