I would say timing is the most important thing. Going through some practice sets helps but  the kind of questions that show up in the test are different from what you see in these practice sets. I anticipated the test to be of the same difficulty level as the ones that these tests portray however the questions were kind of difficult for me. Practice should help in the sense that u get used to the test and its format. Don't panic because the more difficult the questions are the higher is your score. Take it easy :)