Give/sell digital bag tags to frequent flyers

Fill up empty seats by selling affordable return trips to unknown/secret destinations. Pick the destinations among those that have low occupancy close to departure time.

Make the app as lightweight as possible. Remove images, animations and leave only the bare necessities. This saves data transfer and storage - which in turn saves energy.

Find ways to allow tax-free purchases to be done in departing airport and to be picked up at the airport were I land. It could save a lot of weigh/fuel.

Collaborating with local governments to create urban air mobility solutions, such as electric air taxis for short-haul trips, can reduce the reliance on traditional trans

Even if you have a few seats in business. The planes will be filled as usual while providing better service with almost no additional carbon footprint.