1) Regularly reading articles from The Economist
2) Getting a good idiom list that is relevant to the GMAT
3) Recognizing that it is not simply about understanding the fundamentals at a certain point. That it can also be about your approach.
4) Taking the time to review questions during your studies (*not only figuring out why an answer choice is correct but why others are wrong or irrelevant)
5) Improving your stamina
6) Knowing when to "let go" or "meh" - (This is harder than it sounds. Even on my V48, I got sucked into one question).