A useful revision session leaves you with evidence: what you could answer without help, what you missed and what you will do next. Start small enough to repeat the routine, rather than trying to revise everything at once.
Spaced repetition means returning to material across separate sessions instead of repeating everything in one sitting. Flashcard reviews work best when you try to recall the answer first and let your next review reflect how well you remembered it.
A good flashcard asks something specific and gives you an answer you can judge. The aim is not to move every sentence of your notes into a deck—it is to create useful prompts for independent recall.
If you need to remember key facts, make a small deck and review it. If you need to apply an idea, try topic questions and use mistakes to choose your next practice.