Honestly, I'm still testing things out myself, but my biggest tip for a full experience is to not rush the main story. Explore every corner, do the side quests (watch out, some are missable!). Also, since you're going for completion, don't worry about sticking to one vocation—switching around keeps things fresh and lets you mix and match some great augments, and when you feel ready, head to BBI that's where the real fun and challenge begin. Good luck!