Not handing out napkins under every drink.

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

Separate the salt and pepper from the rest of the table set. Way too often it's just thrown away.

More level points to trips that are more sustainable and have less legs and layovers to promote more direct travel.

Mount small blades on the side of the wheels to make them spin by themselves before landing to reduce tyre wear upon contact with tarmac.

Stop Printing menus for biz class, make them available on the monitor.