As a leader, when you walk through the door, you're on stage. Your every move is being watched and imitated by your employees. Therefore, you must be consistent and predictable in how you interact with your employees and how you deal with life’s (organization) challenges.
Your attitude is the foundation for your employees’ attitude. If you come in to work smiling, optimistic and approachable, then it's easier to expect a positive work day. If you come to work with a scowl on your face, are angry or have a "don't talk to me until I've had my coffee" attitude, you can expect to be working in a negative work environment - and have no one to blame but yourself.