People trust and follow leaders who are congruent, that is who "live in accord with the promptings that come from their true self" (Herman Hesse). Another way of expressing this is that true leaders operate from a high degree of personal integrity.
Stephen Covey and Jim Collins and others frequently express the idea that leaders should articulate their purpose, mission, core values, and other elements of their strategic direction. Now Jeff Belkora has developed a process for doing this called Ethical Coding.