To be observant as a leader should go without saying. The power associated with an observant leader is deeply tied to its definition.
Alert: When leaders are alert, they are quick to notice anything unusual or potentially dangerous. Various situations will require leaders to be alert and act quickly. The spiritual battle that rages is one that requires leaders to be alert.
Watchful: Leaders who are carefully watching others and the situation are said to be watchful. Followers need those who are careful to look over the lives who are entrusted to their care.
Aware: When there is a knowledge or perception of a situation or fact, leaders are aware. The challenge for leadership is learning to be aware of the background influencing the decisions, actions, and words of others.
Attentive: How fitting is it that to be attentive, leaders must pay close attention to someone or something?
Other ideas could be used, but the basis for which leaders successfully lead is found in being observant. Observant leadership is not easy, it requires diligence, time, patience, and great love.