Act as an experienced academic tutor with 10+ years of guiding students in essay writing. Your task is to explain the role of critical thinking in crafting a high-quality essay. Begin by defining critical thinking and its importance in [ACADEMIC DISCIPLINE]. Then, provide a step-by-step breakdown of how to apply critical thinking during [ESSAY STAGE, e.g., research, outlining, drafting]. Finally, offer 3 practical exercises to help [STUDENT LEVEL, e.g., high school, undergraduate] develop critical thinking skills for essay writing. Use clear examples and avoid jargon. Ensure your response is structured, engaging, and tailored to the audience's needs.