Applying sunscreen skincare products every day should be the foundation of your beauty routine. Sun damage is the biggest cause of premature aging. Sunscreen makes the rest of your skin care routine more effective. Our skin works to protect us from harmful ultraviolet radiation, which is why we should use sunscreen to protect us from damaging UV rays. Even on cloudy days, our skin is susceptible to the sun's rays which can lead to skin cancer, discoloration, and wrinkles over time.