I second the other suggestions up above. In addition, I found for myself that taking practice tests ad nauseum, with the same time constraints, was the key to doing well. The first time I took my GREs, I did horribly (It didn't help that my newborn son was in his colicky stage). And believe me I studied! The second time, I just made it a habit to take some version of the practice test day in and day out. If anything else, it changed what had been an anxiety ridden event into a daily chore that had to be done and over with. My score jumped significantly the second time around.