Always Do A Good Job

I've seen one quality that sets apart good employees from bad ones. The good ones ALWAYS do a good job, no matter the circumstances. Even if they're unable to know everything, they have the problem solving skills to find the right information. 

You don't have to know everything, you just have to know how to deliver a good product. That could be an email, a presentation or a phone call. Always do a good job. Even on the most meaningless seeming tasks like sweeping a floor. Set the standard of always doing a good job, no matter what you're doing.