I like going in blind, because like has been said, you can only really do it once. But I usually don't get around to playing games a second time anymore and don't like missing stuff. So I go case by case anymore. I'm playing Undertale now and I'm not about to ruin it by looking up a walkthrough. At the same time, playing something like Lightning Returns where they dump into it and give little information on what to do AND give you a time limit, I'll look up what to do then. And on that note, if there's a time limit I will use a guide, because time limits suck.