We love the look of denim on denim. While the vibe is inherently casual, there is a simple way to elevate the ensemble if you do need a more formal vibe for a last-minute event. Just ask Gigi Hadid! While at the U.S. Open this week, Gigi opted for a slightly cropped short-sleeve chambray shirt with coordinating skinny jeans, and dressed up her overall look with an attractive silk scarf tied around her neck.