Use your PSAT scores to help you determine where to target your studying. If you receive a high score in math, but do poorly in identifying sentence errors or other grammar-based questions, you know that you need to spend more time studying your English grammar before taking the SAT. Each section of the PSAT will have an overall score as well as scores for the individual parts of the section. While you should study for all parts of the SAT, spend more time on the areas where you received the lowest scores.
Whether you took the PSAT as a freshman, sophomore or junior, you are still continuing your high school education. Paying attention in class, reading your assigned texts and working your hardest in your classes will go a long way toward helping you improve your test scores. The SAT tests your aptitude for learning. The more you learn and the more you practice the skill of acquiring knowledge, the higher you will score when this aptitude is measured.
Take advantage of the abundance of available SAT study guides to practice for the test. These study guides are made expressly for the purpose of aiding students in studying for and scoring better on the SAT. The practice tests and questions in the study guides are similar to those you will find on the SAT. If you use the practice tests, you will know exactly what you need to study and improve on, and what subjects you have under control. You will also familiarize yourself with the way the SAT asks questions, which may have been a problem on the PSAT if you weren't used to the particular wording of the questions and answers.
Part of good test-taking is to be mentally and physically prepared on test day. Get your supplies -- sharpened pencils, snacks, ID, test ticket, comfortable clothing -- ready the night before. Have your route to the test planned out, and know when you need to leave to get there in plenty of time. Get plenty of sleep the night before the test, and set your alarm so you don't have to rush around to get ready. If you can eliminate some of the anxiety of taking the SAT, you'll have a clearer head that is better able to answer the test questions.