Every time I flew I would make a comment to my F/O and F/E to the effect that they should not hesitate to point out something wrong, if they saw it.
I briefed the Cockpit F/A to let me know if there was something amiss in the cabin that I should be aware of.
That's called "Common Sense".
[This message has been edited by I. M. Esperto (edited 14 May 2001).]