Alessandra Rich’s polka dots have long been a fixture in the Princess’s wardrobe—she’s worn the designer’s modern teadresses to both Wimbledon and Royal Ascot, as well as in royal family portraits. And when she’s in Balmoral mode—think skinny jeans, Barbour jackets, and the odd divisive baker boy hat—Kate enjoys introducing a splash of tartan.

Consider Kate’s timeless silhouette a modern take on back-to-school dressing. Your nostalgic nods to school uniform (adult women co-opted Mary Jane flats and Pointelle socks from the playground a while ago now) won’t veer into costume territory if you, like the Princess, keep things classic.