Beauty Rosie Huntington-Whiteley Tells Us the Secret to Supermodel Hair By Marianne Mychaskiw Marianne Mychaskiw Instagram Marianne Mychaskiw is a New York-based freelance writer and editor who covers everything from beauty and style, to wellness and entertainment. InStyle's editorial guidelines Published on September 19, 2014 @ 11:02AM Pin Share Tweet Email Photo: Andrew Toth/FilmMagic There are a few universal truths in life, and the fact that Rosie Huntington-Whiteley will forever have perfect hair is one of them. At the launch of Moroccanoil’s Inspired By Women video campaign series, which was directed by Bryce Dallas Howard and features six influential women including the model, we just had to ask her the secret to her flawless strands. One key tip: When you find your mane man or woman, never let the person go. "The most important thing for me is to make sure I get regular cuts. I'm very loyal to the people I work with—George Northwood has been my hairdresser in the U.K. since I was 16, and he was in his early 20s," she tells InStyle. "He was a junior hairdresser and I was an up-and-coming model with no money and I'd go to him because he gave cheap haircuts. We've been working together ever since, and now, he's just opened his own salon in London!" Sticking to the same pro holds more benefits than lively salon conversation: Your hairstylist will really be able to get acquainted with your stands, and can best determine how to work with your hair's natural movement while keeping it at its healthiest. We also assume they'll be completely honest in moments when you're tempted to make a spontaneous post-breakup chop like we have. Quality products and giving her hair some downtime is also a must for the model. "I try to keep my hair and makeup pretty simple when I'm not working," she says. "I've been using the Moroccanoil Treatment Oil ($43; moroccanoil.com) for about five or six years now. I put a small amount in my hair while it's still wet, and I'll blow-dry it in. It makes my hair more manageable and easy to style, and gives a lot of shine with good texture." That, combined with a nourishing deep conditioner, keeps Huntington-Whiteley's strands healthy no matter how many heat-styling tools are being used backstage, though it took a hard hair lesson for the star to develop her easy-does-it routine. "When I was about 14, I begged my mom to do one of those brush-in highlight kits on me, and I ended up coming out with five massive one-inch streaks in my beautiful, untouched hair! We must have used 10 to 15 boxes trying to get it fixed, but that was something I had to learn early on," she tells us, laughing. "I remember my mom telling me, you don't want to change what you have, you should always enhance it, so that quickly became my beauty philosophy." Click through to see yourself in Rosie's gorgeous waves—no glam squad required.