In fact honesty is the ONLY policy! According to Kouzes and Posner in the Leadership Challenge, Honesty is the most identified trait of Leaders that others want to follow. It may not be the trait which gets you promoted, but it is definitely the trait that if not practiced will get you fired, or lead to divorce, or see you alone with no friends. 

Honesty does take courage. It can be difficult to be honest when a “little” lie will get you out of trouble. Being honest when faced with the easy option to lie is the mark of true character. Honesty really is the best (and only) policy. Being honest is a foundational character trait. It means telling the truth regardless of the consequences; even if the truth is that you failed, being honest means you own up to the failure, and take the consequences. 

If you made a mistake or dropped the ball on a project admit it, apologize, take the consequences as the cost of learning and move on.  Covering up mistakes or blaming others erodes your leadership and your soul.  Honesty is the best policy.