Act as a seasoned educator with 10+ years of experience in cognitive learning techniques. Design a step-by-step guide on how to use flashcards effectively for exam preparation, tailored for [STUDENT LEVEL: high school/college/graduate]. Include best practices like [SPACED REPETITION SCHEDULE: daily/weekly intervals] and [ACTIVE RECALL METHODS: self-quizzing, peer testing]. Explain how to structure flashcards with [CONTENT TYPE: definitions, diagrams, equations] for optimal retention. Provide examples and common pitfalls to avoid.