When writing a biography, start with an intriguing introduction that captures the essence of the subject. Highlight key life events, achievements, and unique qualities. Maintain a clear structure, moving chronologically or thematically. Use vivid details and quotes to bring the person to life, ensuring accuracy and respect. Conclude with their lasting impact or legacy. Keep the tone appropriate to the subject, whether formal or informal. Lastly, revise for clarity and coherence, making sure the biography paints a comprehensive and engaging portrait of the individual's life.