My face has had a routine for ages but I only just noticed how much my neck and chest have been left out, and they are telling on me now. Crepey texture on the neck, a bit of sun mottling on the chest from a lifetime of sundresses and zero SPF below the jaw. I know the answer probably starts with actually extending sunscreen down there every day, which I am now doing. Beyond that, is it worth bringing my retinol and vitamin C down onto the neck and chest, and if so, do you go slower there because the skin is thinner and more prone to irritation? Anyone who has worked on this area for a while, did it respond, and how long did it take before you saw anything? Managing my expectations here.