Divide the number of questions by the number of minutes for the exam to determine the amount of time available for each question. Planning your time in advance will prevent you from wasting 20 minutes on a single particularly difficult question instead of continuing on to answer other questions correctly.
When uncertain, cross out choices you know are incorrect before making your selection. Eliminating just two answer choices moves you two possibilities closer to the right answer.
Questions that include words of absolute certainty require equally certain answers. Words such as "never" and "always" mean that the correct answer choice offers no room for exceptions. Conversely, questions that contain words such as "typically" or "often" require answers with equally flexible phrasing.
Read the entire question while inserting each possible answer choice at the end. Connecting each answer choice to the question helps illuminate inaccuracies hidden by reading the question and answers separately. For example, say the question is, "All chickens begin as ____." You should insert each of the possible answers -- All chickens begin as [A: fish] All chickens begin as [B: tadpoles] All chickens begin as [C: chicks] -- and weigh the options to decide which answer fits best.
After reading all possible answers, trust your first instinct. Stick with your first choice unless you find flawed logic in your original answer or you remember conflicting information. Changing your first answer choice because of a feeling or hunch is likely to backfire.
Read through each possible answer before selecting your choice. Multiple-choice questions often break into multiple parts. Answer A might appear correct until you read answer choice C. If you choose answer A without reading the others, you won't realize that answer C provides a more complete answer.