Essential resources for preparing for the Geography optional in UPSC include a combination of textbooks, NCERTs, and reference materials like Strahler and Rudranath Dutta. Online platforms offering video lectures and mock tests are also invaluable. Additionally, candidates should engage in current affairs, as they directly connect theory with practical application. Participation in study groups can enhance understanding through discussions. Effective time management is crucial, ensuring that all topics are covered thoroughly before the exam.