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.

In Plus and Business on long haul - hand out amenity kits by request instead of placing them on all seats.

Reuse condensation water on planes from ACs for use in toilets and other non-drinking water places.

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.

Offer rebate to business class passengers for not using the full luggage quota.

Stop tankering on flights, lighter aircraft less fuel burnt and on shorter flights possibility to save deicing.