The Courtin-Clarins girls — four twentysomething granddaughters of brand founder Jacques Clarins — aren't just pretty faces. They're born-and-bred beauty gurus whose glowing complexions are testament to the line's effectiveness. Check out their summer beauty tips, then shop the sale and read more on StyleFile. Virginie: "Never forget to put your SPF on!” Prisca: "Moisturize, moisturize, moisturize.” Jenna: "If you know you’ll be taking party pics at night, wear a little more foundation, because the flash is so strong and the lights wash you out." Claire: "I always bring a full case of travel products on long distance flights. It’s a moment when your skin needs the most help."