Key analytical skills that UPSC candidates should develop for effective preparation include critical thinking, problem-solving, and data interpretation. Mastering critical thinking enables candidates to evaluate various viewpoints and formulate well-reasoned arguments. Problem-solving skills enhance their ability to tackle complex questions in a structured manner, ensuring clarity in thought and expression. Additionally, being adept at data interpretation allows candidates to analyze statistics and graphs, which are often integral in subjects like economics and environment. Strengthening these skills through continuous practice and application will significantly benefit their overall performance in the UPSC exam.