Children and adolescents in a summer tennis instruction program were taught a "metaphor method" for eliminating distractions and detrimental ideation. They visualized themselves enclosed in a bubble, cocoon, or chrysalis that separated them from nontask stimuli. Although subjects in the experimental and control groups were positive in their evaluations of their tennis experience, ratings from instructors demonstrated multiple advantages of the metaphor method. When compared to control group subjects receiving regular instruction, students taught to use boundary metaphors improved significantly in terms of performance criteria and ability to concentrate. Their instructors also rated them significantly higher in enjoyment of the experience, motivation, and a display of mature and appropriate behavior. The method was easy to implement and appears adaptable to a variety of sports and other performance settings.