Use any opportunity to improve your skills in reading, writing, mathematics and critical thinking. Strengthening these areas will not only increase your chances of a high PSAT score, but it will serve you well in academics and in your future career. You can't acquire them during an overnight study session.
Visit the College Board's PSAT/NMSQT test prep website (see Resources). This website will introduce you to the content of the PSAT and provide helpful test-taking strategies and practice questions.
Procure a copy of the Official Student Guide to the PSAT/NMSQT from your guidance counselor. The guide contains a practice test for that year. Work through the booklet to familiarize yourself with the types of questions the PSAT will ask you. The College Board provides full explanations of these questions on its website. Study guides and practice tests produced by independent companies are also available at libraries and bookstores.
Enroll in a PSAT prep course or hire a private tutor. If you are having trouble studying on your own, the more personalized, guided help may be well worth the price (see Resources).