Speeches: stand tall on a stool and deliver a one-minute speech on anything. Do one a day; put topics in a hat--he draws one out and speaks on it. Topics might be ketchup, crime, how sandwiches are made, how to clean up one's room. Ge can expostulate and iterate on most any topic, for a full minute--with everyone watching and clapping at the end. (For more ideas, read our ebook, Learn to Speak with Ease.)
Ever progressing on piano ...youtube it...because practice uses up time PRODUCTIVELY becoming something better than you were i.e. an eventual ego booster. Have him or her work through our self-taught, easy-to-do Quick Piano course.
Inventions and problem solving over a practical project. Fix these wheels, adjust that brake cable, repair a door hinge, clean out the drain pipe under the kitchen sink....
Woodworking.-- shop kinds of things. My hubby made a little stool/table in 9th grade and to this day is still proud of it. My brother made a wooden chess board and was way proud of it. My cousin built a chest out of aspen wood.
Fixing one meal a month, or a week, perhaps (if necessary and allowable, budget-wise) using one of those delivered-to-your-door meal preparation boxes.
Writing the story of his life so far....
For thoughts on the broader topic, see these resources: