For the extraverts, it's more of just stopping and allowing yourself to look within yourself for what you perceive from inside. It's about stopping to think about personal desires over the external world.
Say, for an ExTP, they have lived off of Se or Ne for a while, but to be more balanced, they need to develop Ti. The problem they're going to face is that they have lived their life off of perception. They've gone with impulses, moved with the flow, and not stopped to think about potential setbacks. Ti involves dissecting things to figure out how they work. For an ExTP, it means introverting for the sake of understanding an action you're taking. Ti allows you to take the action and analyze it internally in order to refine it.
For an ExFJ, Ni and Si are introverted perception. They've lived off of Fe, primary outward judgment focused on harmonious relationships. In a sense, they've "gone with the flow" and allowed themselves to be influenced almost entirely by the extraverted feeling judgments. This works the majority of the time, as the outward judgment allows them to get things done and accommodate other people, but it fails to accommodate the person using it. It allows them to focus on themselves as well as have inner perception to add to the outward judgment.
Si is a function that focuses on the past. In using Si, the ESFJ is able to recall past experiences in great detail. ESFJs dig into Si to remember how the Fe judgments were done before and worked. In a way, they use Si to stabilize the present. In doing this, they're able to modify present actions by recalling what has worked before.
Ni is a function that focuses on the future and possibilities. It takes an idea, and improves on it. For an ENFJ, they use Ni to focus on people. An ENFJ looks at someone and sees potential, and wants to help them reach their potential. Like an ESFJ, they have relied on Extraverted Feeling judgment to live and are using judging standards that change with the situation, letting themselves be affected greatly by each situation. To use Ni, an ENFJ is able to use the intuition to see what's "over the horizon" when using Fe. Instead of being dominated by each situation with Fe, they can take the use of Fe in the situation and focus their intuition on the people they're judging, seeing the potential in the people around them.
Err. Why did I pick ExFJs? LOL. Ok. It works the same for ExTJs, anyway.
