Don't overload your skin with chemicals by using an SPF cream on dull winter days. Sunscreen is a must from April to early October. Use a vitamin-rich cream during the rest of the year. Some incorporate a special pollution complex, usually a cocktail of antioxidant vitamins, such as Clarins Multi-Active Day Cream, £30. Other good bets are RoC Hydra Plus Vitamins Active, £14.95, Elizabeth Arden Good Morning Skin, £21, and Origins A Perfect World White Tea Skin Guardian, £25 (0800 7314 039 for stockists).