From her Santa Monica bungalow, Haley Alexander van Oosten concocts custom fragrances and plant-based skincare products with 100 percent natural oils. "Everything about L'Oeil du Vert is hand-crafted," she says of her line, which comes in vials embossed with a logo derived from a seventeenth-century alchemical symbol. Van Oosten's managed to maintain a relatively low profile so far, but that might change with her next project: She's creating a collection of essential oils for A.P.C. "It's an interesting fit," says van Oosten, who met A.P.C. founder Jean Touitou through their mutual friend Lisa Eisner. "Jean is very much a connoisseur, and in that sense you can see that he really appreciates the purity of this project." When we quizzed Touitou for more details on the collaboration, which bows at the end of the year, he had only this to say: "I'm warning you: It's addictive. You're in trouble."