Fellow speaker,
World Champion Speaker Craig Valentine recommends using "visual and verbal" callbacks. So to do a callback to something that happened previously in your story, point to the part of the stage where you were talking about that part of your story and describe what happened there. For example, if you have been talking about you as a child and want to callback to that moment, point to the part of the stage where you talked about being a child and say, "When I was a child..."
V-ed,
Tim
