Notes can look complete while leaving you unsure what you remember. Turning some of them into questions creates a practical way to revisit the material. Begin with the ideas that matter most to your present learning goal.
Ask for explanations as well as definitions. A question such as how two concepts differ encourages you to describe their relationship. Add an example or a small application when the topic allows it.
Answer without looking at the source, then check your response. Where it is incomplete, write the missing step clearly rather than copying an entire page. Keep the source reference so that you can return to the surrounding context.
Review a manageable selection over time and retire questions that no longer help. The aim is to build usable understanding, not an ever-growing collection of cards. Adjust the method when a subject requires practice, discussion or direct observation alongside reading.