Yves Saint Laurent jacket

Power dressing is back, and this time the real "power" lies in the fact that women can dictate what they wear in the office and still come across as professional. This summer, wherever you go, whatever you're doing, a perfectly cut blazer is an investment worth making. Navy is actually more versatile than black and is easier to pair with brighter colours, making the Yves Saint Laurent jersey jacket (£1,110) a great investment. Yes, it's a lot of dough for a jacket, but Stefano Pilati has redefined the cut of the classic boyfriend blazer and engineered a casual, fabric-like jersey to make it mind bogglingly luxurious.