Dunlosky and colleagues report that spreading out your studying over time and quizzing yourself on material before the big test are highly effective learning strategies. Both techniques have been shown to boost students’ performance across many different kinds of tests, and their effectiveness has been repeatedly demonstrated for students of all ages.
Teachers, parents, and students would be wise to focus on these strategies for learning instead of the less effective strategies like summarizing and highlighting. Here's the full study:
Improving Students’ Learning With Effective Learning Techniques: Promising Directions From Cognitive and Educational Psychology