Call it the Rihanna effect, because there have been a lot of one-sided brush-back for red carpet hairstyles since the singer shaved one side of her head, letting her Barbie lengths swish over the opposite shoulder, not least on ol’ lion finger Cara Delevingne who wore this style at both the Met Gala and last night’s Gatsby screening in Cannes. 

Last night’s half-up do was held messily into place with a pair of vintage-looking jewelled barrettes, which not only added suitable opulence to her look for the film festival with more glamour than an Upper East blow-dry bar before brunch hour, but made re-creating your own equally dishevelled version look as simple as a sweep and a clip. Dig out your showiest earrings and try it now.