According to IIA guidance, the practice by the chief audit executive (CAE) that best enhances the organizational independence of the internal audit activity is meeting privately with the board at least annually.
This practice ensures that the internal audit activity can operate independently of management and directly report and discuss significant matters with the board, which is critical for maintaining its independence and objectivity.References: The Institute of Internal Auditors (IIA) - International Standards for the Professional Practice of Internal Auditing.