This document provides tips and examples for proofreading documents to catch mistakes. It discusses the difference between editing and proofreading and emphasizes closely examining all aspects of a document. Common mistakes discussed include typos, punctuation errors, factual inaccuracies, bad formatting, and copyright issues. The document provides many examples of real-world mistakes and discusses the importance of proofreading various types of media like print, online, and social media. It emphasizes taking one's time and having a careful eye to catch any errors.