Yeah, time is the BIGGEST killer on that test!! Watch out. Also, I found that when the reading section came around I relaxed since it's not that tough. BIG MISTAKE! I took the ASTB twice before being Pro-rec'd and that hurt me both times. I had to start getting into the mind-set during the test that I can focus and stay alert for three hours when the results of those three hours can/will determ an awesome career.
Also, when it comes to the Aviation and Nautical section, some of the questions can be answered by just crossing out the obvious wrong answers...some though are just general knowledge in that area. Do you have your PPL? Or, have you taken some flight lessons?