The seven key principles of effective leadership development are: 1) Provide training for leadership roles before placing someone in a leadership position. 2) Carefully select leaders based on their skills and qualities. 3) Use line managers as mentors to guide and counsel potential leaders. 4) Create opportunities for people to take on leadership challenges. 5) Educate leaders through various teaching methods. 6) Develop a long-term, multi-component strategy for leadership growth. 7) Involve the chief executive as a leadership example.