Founder of French skincare line Caudalíe, Mathilde Thomas creates products that are both effective and natural. She uses potent active ingredients found in grapes, many of which are grown in Bordeaux vineyards, and has banned pthalates, parabens and other harmful preservatives from all Caudalíe products. Thomas promotes sustainable development in other areas, too: the company has lowered carbon dioxide emissions and uses recycled paper for mailings and packaging. Click through for her four beauty must-haves. >