The degree of psychological fitness will ultimately impact mission outcomes, so approaches to enhancing it are critical. Performance psychology is one important aspect of psychological fitness that fits into the holistic model of human performance optimization. This article delves into one component of performance psychology: how mental skill training can be applied to improve performance on mission-related tasks. Mental skills training provides added internal resources to help meet the extraordinary external demands that Special Operations Forces personnel can face. Relevance in terms of the demand-resource model and the positive psychology concept of flow are explained. The application of two specific mental skills-executing a goal-setting process and using mental imagery to rehearse technical, tactical, and strategic tasks-will be discussed by using the example of how to enhance performance when entering and clearing rooms.