Korres Golden Krocus Ageless Saffron Elixir Serum ($98) helps correct visible signs of ageing with its krocus flowers that bloom only one time per year in Kozani, Greece. These flowers are hand-picked and hand-separated to preserve their antioxidant properties. Then, the zero-waste, sustainable operation means the unused parts of the flowers are added to the soil as organic fertilizer for the following year's harvest.