I would use my skills in optimization and deep learning to learn what frequenzies and time schedules that maximizes the load factor of each aircraft in the fleet.

Offer a ”Sustainable Comfort Kit” with eco-friendly amenities like reusable water bottles, organic snacks and bamboo sleep accessories

SAS connects Scandinavia with Europe, through hubs and trains. Fly to a hub, get a train to your destination.

Reduce the amount of items on meal trays. Stock to the main and a piece of bread or a salad. No need for all these extra individually wrapped items, dessert etc.

If possible, adjust aircraft speed to reduse fuel consumtion

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.