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.
Now, a lot of people mistaken a serum as a light moisturiser. I've heard girls talk about only wearing serums for the hot summer weather. This isn't the way to go. A serum and a moisturiser is designed to work in conjunction with each other, not alone.