Aspirants should prepare for the Mental Ability section in UPSC Prelims through dedicated practice and strategy. Begin by familiarizing yourself with the types of questions frequently asked, such as numerical ability, data interpretation, and logical reasoning. Utilize study materials specifically tailored for this section, engaging with online quizzes and question banks. Regularly timed practice is crucial to improve speed and accuracy. Joining coaching classes or study groups can also provide structured guidance and support through peer learning and sharing of techniques.