How ISFPs 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, an ISFP can achieve personal growth by developing those functions that are not fully developed, through actions such as learning how to express disagreement or criticism in a constructive way, making and implementing detailed plans, or giving direct instructions when it is appropriate to do so. You may need to learn to be more open about your personal values, so it is less of a surprise when colleagues infringe them, and establish a long term goal to work towards.
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: ISFP and Stress