To improve string manipulation skills for competitive programming, focus on practicing a variety of string-related problems, including pattern matching, string search, and transformations. Mastery of built-in string functions in your chosen programming language, such as substring, concatenation, and regular expressions, is essential for writing efficient code. Understanding common algorithms like KMP (Knuth-Morris-Pratt) for pattern matching, Rabin-Karp for substring search, and Trie structures for efficient dictionary operations helps in handling complex string problems efficiently. Additionally, practicing problems on topics like palindrome checks, longest common substrings, and character frequency analysis helps build a solid foundation. Regular practice enables competitive programmers to solve string problems quickly and with fewer errors, making string manipulation a key area in contests.