Athletic coaches talk about stressing the fundamentals: blocking and tackling in football, dribbling and passing in basketball, etc. The same idea applies to Academic Games as well.
For instance, in Presidents, students should be able to identify the 5-10 facts about each Chief Executive that are the most commonly used in clues. Make your players memorize those possible clues. They can build additional knowledge on that base. They should get at least 2 points on every question.