Be respectful of calendars. When I block off some time to focus on a hard problem, they don't interrupt me. If something does come up, they cautiously IM, "when would be a good time for an important interruption?" and nothing else. No phone calls, no swinging by my desk, no details of the issue, etc.
Everybody is treated with respect and not looked down upon, not even the cleaning personnel. It creates an atmosphere of trust and wholesomeness, that intrinsically motivates the people that work here. People are encouraged to speak up when they see possible improvement without the fear of mistreatment or sanctions (which is another good thing, too).
Managers that are both advocate and agent for their direct reports do wonders for a team's ability to produce.