Sunscreens

The product with the best evidence behind it, and the one most often applied too thinly. Broad-spectrum cover matters more than the SPF number, because UVA drives visible ageing and passes straight through glass. Modern filters such as Tinosorb, Mexoryl and TriAsorb are more photostable than older ones and cosmetically far better, which matters because the sunscreen that works is the one you will wear daily and reapply.