La Maison Ani, Knightsbridge
This glitzy French restaurant in Knightsbridge has been discovered by the royal family recently, with Princess Eugenie heading there for dinner with Lady Kitty Spencer and her sisters. But its ultra-Instagrammable interiors (think pink banquettes and marble counters) and chic Mediterranean menu gives it a fashionable edge too. Dine on lobster salad, steak tartare and truffle rigatoni while discussing your favourite looks of the day.
The Carlton Tower, 1 Cadogan Pl, London SW1X 9PY, lamaisonani.com