As one of the few humans who looks amazing with basically no makeup and a messy hair nest in her face, Charlotte Gainsbourg's approach to fashion is noncommittal: "Style for me is a casual way of putting something on. It’s not thought out but needs to suit your way of life. Now I like wearing the same sweater over and over again, then taking it off when it’s smelly." She covers the women's spring fashion issue of WSJ. magazine, out this weekend.