There's a degree of word of mouth; if my friends are all over smth, ill check it out. (besides omgcp. i cant for the life of me navigate that site)
on tapastic, i mostly.. dont? ive developed a fairly large itinery of comics i enjoy, so its rare that i pick up a new series. most of them comics are from forums, actually, primarily ones about LGBT comics (and a recent one for sharing comics with small fanbases. it pays off to trundle through a lot of stuff you dont like on threads like that because you can find some true gold) - theres also, of course, the occasional few from trending or highlight.
now and then, when im looking for smth new, ill go on 'fresh' and pick 3 comics from the first page to check out - ive really loved some of them, but it is a bit hit n miss.
when it comes to print comics i just dont. i (reluctantly) read a lot of marvel because ive been invested in it for years, and it takes up so much time i only read one or two non-marvel titles. i see a lot of comics my friends like, ones i want to check out, but for now its a distant dream...