Alexa Chung, snapped in London at the weekend, tweeted, "Arriving in pajamas to talk about personal style at the Vogue Festival. #wardrobecrisis." But who'd have known there was a wardrobe crisis underneath that coat? By simply tossing on a belted trench and pushing the sleeves up (deliberately leaving the cuffs of her shirt poking out), then adding a tan boot and bare legs, she took the look from bedroom to brilliant.

Here's another styling trick to try this week.