Isabella Blow with Horns, Gloucestershire, 1996© Juergen TellerEver since she strung a daisy chain of jewel-coloured taxis along the concrete balustrades of J. Crew’s Regent Street store this September, Shona Heath has been the biggest name in set design. But really she’s been wearing that crown for about a decade now. As the go-to creative director for the likes of Dior, Prada, Miu Miu, Hermès and Mulberry, hers is the eye that frames each new season’s collections, and she is a re...