Make sure you know how to do everything on the two latest official exams. The older ones are too easy, don't even waste your time doing them.
There's a free test published by Charles Rambo that's probably the single best piece of prep out there. I think he's got another exam or two if you want to pay him for them. I didn't.
Schaum's Outlines are incredibly useful for getting fast and consistent at mid-tier calculus problems. Download a few and grind the hell out of any weak spots you have.
One tip I don't see posted very often (in fact, some dumbasses post the opposite) is to make sure you don't skip ANYTHING in review. If you get a question on something more niche, e.g. the divergence theorem, it will be 100% free if you remember the theorem at all. You're throwing away free points by skipping stuff that doesn't show up often.