For improving full body interaction in an interactive storytelling scenario, we conducted a study to get a user-defined gesture set. 22 users performed 251 gestures while running through the story script with real interaction disabled, but with hints of what set of actions was currently requested by the application. We describe our interaction design process, starting with the conduction of the study, continuing with the analysis of the recorded data including the creation of gesture taxonomy and the selection of gesture candidates, and ending with the integration of the gestures in our application.