Commonly suggested study materials for the UPSC CSAT paper include basic mathematics textbooks, comprehension passages, and dedicated guides for logical reasoning and analytical ability. Resources like R.S. Aggarwal's books and previous years' question papers help in understanding the exam pattern. Additionally, online tests and mock exams serve as excellent practice tools. Focusing on improving reading comprehension and analytical skill is essential, as they often play a critical role in achieving a good score in the CSAT section.