I am looking old and need to get on top of skincare. Could someone explain sunscreen to me? I currently wear the Laura Mercier tinted moisturiser which says SPF30 - is that enough, or should I be doing more? A separate facial sunscreen? Under makeup? And all year round? I tried a sample of the REN one last year but I looked really shiny so abandoned it. I have very fair skin which burns easily and look about 300 years old at the moment (I’m 42) if that helps.