Hi there! The most obvious way to improve your score is independent-study: complete as many practice problems as possible, take full-length practice exams under timed conditions,etc. A tutor may help with some fundamentals strategies and approaches to questions that you may not have considered in the past. A third-party can also add value by analyzing your strengths and weaknesses, and customizing a learning experience to your needs.
Full disclosure: Idalia is an academic advisor and private tutor for Parliament Tutors in Miami.