In small airports, like Vigra, where there only 1 or 2 airplanes stand, have roofs like carports to prevent snow on plane. This will reduce amount of deicing fluid needed.

When the crew collects trash before landing, why not make separate rounds for collecting, cans, plastic cups, paper, etc instead of collecting all trash in the same bin.

In order to maximum cabin factor, offer Eurobonus tickets on all flights

Include meal information as early as possible in-app.
This is good for people with allergies, so they abstain from it.

Let it be easy to take steps when buying bio-fuel.

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