You might enjoy doing type role-playing as an exercise. I often do this in a seemingly random pattern based on what I'm interested in at the moment. You might prefer to define it as a specific exercise with a specific time period. Focus on each of your least developed cognitive functions for a day, such as:
Monday: introverted thinking
Tuesday: extraverted thinking
Wednesday: introverted intuition
Thursday: extraverted intuition
Friday: Relax and be your normal self. By now, your friends are wondering if you have multiple personality disorder or something!
At the beginning of each day, read about that function and what it involves, and focus on that in each situation that comes up throughout the day in all aspects of life: work, home, financial, social, and others. You could do this for more than a day, but I'd get bored with focusing on only one function for that long.
You'll find that just by considering this exercise, you've engaged your other cognitive functions. Sneaky.
You could even get really crazy and expand this into pretending to be some type such as an INTP or ENTJ for a day. Just don't be afraid to bail out and go back to being a ISFJ if you start to scare yourself.
