In a recent interview with The Times she cited a denim skirt, sunglasses, a cowboy hat and "the right wellies" as her festival essentials.

BBC: Glamming-up Glastonbury Festival

From Serena's denim skirt and boot combo to Venus's designer dresses, there isn't much that the sisters have not tried to wear on the court.

CNN: The highs and lows of the Williams sisters' wardrobe

My favorite look is that of a model wearing a denim shirt with a glittering sequined skirt and ball cap.

FORBES: NYFW Day 6: Tory Burch, Victoria Victoria Beckham, J. Crew, Jenny Packham & Dennis Basso