The more relaxed but equally chic younger sibling to downtown’s upscale Mario’s boutique, Mario’s 3.10 knows that sometimes we like to dress up even when we’re dressing down. Of course, it’s still all about the designers, and the focus is on the hip ones, like Paul Smith, Theory, M Missoni, and Rag & Bone. They offer only the most up-to-date, sophisticated styles in premium denim, sportswear, and casual wear, and they can tell you exactly how the clothes should be styled and worn. Gossip Girl would approve.