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.

Free coffee only for those who have reusable cups with them. Fee for paper cup or no paper cups at all.

More efficient engines using sustainable aviation fuels combined with optimised flight paths and reduced taxiing time. Only use digital tickets.

Offer multi-flight passes with prebooking conditions to better predict capacity

Use more big size bottles and not small cans/bottles

Implement the potential to offset carbon footprint by CDR technologies like enhanced rock weathering;