Fashion Celebrity Rules By InStyle Editors InStyle Editors Instagram Twitter InStyle's mantra is "Everybody's in," and that means anyone who finds their way to our stories should find themselves reflected in them. We prioritize bringing the right writer to every story and sometimes collaborate as a team to ensure we're including points of view across race, gender expression, body size, skin and hair type, and more. Our editors and writers comprise decades of expertise across the beauty, fashion, lifestyle and wellness spaces in print and digital. We prioritize journalistic integrity, factual accuracy, and also having fun with every story we share. For more about our team, click here. InStyle's editorial guidelines Updated on August 1, 2008 @ 01:28PM Pin Share Tweet Email Photo: Big Australia/Mike Emory/BEImages Celebrity Rules 01 of 09 Rachel Bilson Brian Lindensmith/Patrick McMullen "Forget the old rules. I love white all year round. It's cooler to wear it when you aren't supposed to." 02 of 09 Rihanna Frank Micelotta/Getty Images "The idea of not wearing brown and black together seems so dated. The other day I wore a black T-shirt, black Nobody jeans, a brown leopard-print belt by Dolce & Gabbana, and brown Giuseppe Zanotti shoes, and it looked awesome. And I also love to mix prints." 03 of 09 Ciara Ray Tamarra/Getty "Combine different materials in your accessories. I wear a lot of different bangles-gold, silver, wood, acrylic. It's fun." 04 of 09 Hilary Duff Stephen Trupp/Starmaxinc "I never do one designer all the way, like an entire Dolce & Gabbana outfit. It's not practical. It's more fun to mix your street wear with high fashion." 05 of 09 Janet Jackson Gilbert Flores/CelebrityPhoto "Just because a trend happens doesn't mean you should adopt it. Wear what best fits your shape." 06 of 09 Julianne Moore Radial Press/Startraks "I learned at a young age that physicality isn't important. It can be manipulated." 07 of 09 Keira Knightley Jeff Kravitz/FilmMagic "I love blokes' shirts. I bought a plain white men's Prada shirt in Rome." 08 of 09 Marcia Cross Scott Downie/CelebrityPhoto "Some people think wearing powder ages them, but try it anyway. For me it mattes my makeup and blends it well." 09 of 09 Catherine Zeta-Jones Big Australia/Mike Emory/BEImages "A woman should never wear anything she cannot lose. Why have jewelry in a safe? Stack it on and enjoy!" Click here for more celebrity rule breakers.