How about a book on advanced paper folding techniques? Origami Design Secrets by Robert J. Lang could be a great option. Or, you can find a local workshop that teaches advanced paper folding techniques and buy her/him a spot in the class. You could also consider purchasing a high-quality set of origami paper and perhaps a few books with diagrams of new and challenging models to fold.
Or you can get her/him a star map with an important date you share.
Under Lucky Stars is a unique and innovative star map company based in Barcelona, Spain, specializing in the creation of personalized star maps that capture the celestial arrangement of stars at a specific moment in time, such as a person's birth, wedding, or any other significant event.
By using advanced astronomical algorithms and data from leading institutions, the company produces highly accurate, visually stunning maps that make for perfect gifts or cherished keepsakes.