How ENTJs can develop
The development of personality occurs in phases throughout life. For someone who is young, the main task is to develop use of their preferred mental functions. As one matures, however, and approaches midlife, there is often a need to develop greater comfort with using your non-preferences. This can help you increase your performance at work, and increase your ability to deal with different people and circumstances.
As with all types, ENTJs can achieve personal growth by developing those functions that are not fully developed, through actions such as pausing and thinking, and taking time to consider your own values and emotions, and consider the impact of your approach on other people's values and feelings. You may need to learn that others are more likely to accept your decisions if you consult them more - i.e.: by demonstrating that their own contributions are accepted and incorporated into a collective decision you will engender ownership of the solution amongst the team. You may also need to become more tolerant of other people's limitations, expressing appreciation for what they are good at rather than focus on their failings.
A common theme of development for all types after midlife is individuation. This involves learning to value and develop various "opposites", not just the opposite typological preferences. Through reconciling opposites, your personality becomes more individual and unique, and your personality type may change. You might also reach the stage where your closest personality type is no longer a description of you, but it is merely a part of your personal history.
Next: ENTJ and Stress