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.
This is because the serum is easily absorbed into the skin, while moisturizers work on the surface. If you use the moisturizer first, your skin will not be able to absorb the vitamin c serum. Vitamin C serums are oil free preparations that are perfect for balancing oily skin by exfoliating naturally.