[anonymars]

I meant for flights (edited accordingly). In both cases I think "don't be a dick" probably would go most of the way

[WalterBright]

You'll get treated better by the staff if you dress better.

[anonymars]

I'm less concerned with the behavior of the staff than the behavior of the other passengers

[WalterBright]

The staff can be more inclined to help you if you've got a problem.