Plus: 24 under 24: Welcome to GLAMOUR's first ever Gen-Z power list, I'm a 'Zillennial' – the limbo generation between Millennials and Gen Z – and this is what it's like to be too old for one; too young for the other and Kendall Jenner, Olivia Rodriguez and Hailey Bieber's favourite Reformation dresses are reduced by 40% in this rare Reformation sale