A key way to distinguish between the outward manifestations of Fi and Fe is through morals vs manners.
Introverted Feeling (Fi):
Fi is in essence about morals and inner harmony.
FP types often know better than any other types who they are. They know what they value. They know what they believe in. Strong Fi users will stand firm in their beliefs. They are the kind of people who will hold onto their morals when it is hardest to do so. They don’t really bend their moral rules. Fi can also be a great source for creative inspiration. Many great writers are NFPs and SFPs are often talented in more hands-on crafts.
FP types may occasionally become emotionally selfish. This is often immature/ poorly developed FP types. They will only think about how they feel and will become very irrational when their inner harmony is out of tune. They may also run into problems if they had a hard upbringing. If they have a rough development they may hold prejudiced beliefs and values that are very difficult to change. This is because their morals work in a more black and white manner than the Fe code of conduct.
Extroverted Feeling (Fe):
Fe in essence is about manners and external harmony.
FJ types often very polite. It comes naturally to them. They remember to smile when they greet somebody. They don’t make inappropriate comments. They are naturally accommodating. Go to any FJs house when they are hosting a get together and prepare to be amazed. Strong Fe users are great with diplomacy, human resources and maintaining good public relations. The more philosophical Fe users may have an interest in ethics as well.
FJ types may run into problems when they sugar-coat too much. They may become so absorbed in maintaining group harmony that they sacrifice honesty. They may have a habit of telling half-truths to avoid conflict. They also may have illogical and inconsistent codes of conduct if their Ti is poorly developed. Another potential area of weakness is that their values reflect their culture. This is especially problematic when they live in a destructive culture and/or one that values personality over character. Their values and beliefs may lack depth in this case and they can more easily succumb to peer pressure.
*Keep in mind these are coming from an INTP perspective.