In a week/ some days before a flight, do sell “stand by tickets”, to a cost of approx. Euro 50 in Europa, Euro 200 intercontinental, , to increase the cabin factor.

Use powder soap instead of liquid soap in all lavatories, powder soap is much lighter thus reducing wieght.

Allow lounge guests to opt-out of onboard service and bring their meal and drink to the aircraft

Work together with other airlines/partners to pool up purchases of Sustainable Aviation Fuel.

At check-in and at kiosk ask if they really need paper boarding card or can use SAS app instead.

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.