What do you apply under and/or over it? I bought some recently as I wanted to up my SPF game so bought the SPF40. Usually I would use eyecream, serum, then moisturiser, then if I'm wearing make-up I'd use a primer first. I can't decide which step the cityblock should replace, or if I should be using it as an extra layer but 5 layers seems ridiculous! Where do you use it in your routine?