I urge everyone to bookmark that blog; it is always a fascinating tour of the weirder and wonderfuller places on our planet. And let me leave you with this simply jaw-dropping video of undulatus asperatus in action.
(A sunscreen with a physical block like titanium dioxide or zinc oxide can be applied last, after a serum or moisturizer.) Apply a serum next and, finally, moisturizer if you need it. Polis also recommends serums or sunscreens with moisturizers built in because they save time.
One of the benefits of a vitamin C serum is that they are usually oil free formulations that are suitable for oily skin. They can also be followed with your favorite moisturizer. Serums usually lack creamy, soothing ingredients, so sensitive skin types may need to follow up with a cream or lotion.