Cramming for exams should only be done as a last resort since it is difficult to retain large amounts of information in a short time period. Some tips for effective cramming include eating food to stay energized but avoiding excess sugar, studying in a well-lit place with few distractions, keeping a positive attitude, focusing on the most important topics that will earn the most points, and taking short breaks every hour. It is also important to get at least 3 hours of sleep before the exam if time allows.