Because I am lazy and perhaps stupid and don't feel like figuring out how to link a really old thread to this one, here is a long-winded thing I wrote a long time ago about how I view myself using Fe.
But as for the 'Learned' Fe, which is the purpose of this thread, I think many people associate Fe with social niceties and the more superficial rules, social graces, 'expectations', pleasantries, small talk, etc. And I HAVE had to learn all of that stuff -- and I rather dislike many of the superficial aspects of Fe.
And I think it's the superficial aspects that can be learned -- and give people the notion that Fe is 'fake' - because Fe CAN be fake - especially if it's someone just trying to go through the motions of being Fe so as to get along, or whatever.
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My take on Fe:
Often it's a lot more what I *don't* do, as opposed to what I do do. And fine-tuning based on the individual. It's highly individualized. For example, not saying something if I know the other person is extremely opposed to my thought/opinion. Or fine-tuning my delivery or what I talk about to the specific person, based on what their interests might be, or what their interpersonal needs are. Do they like things to be more to the point? Ok, I can do that. And that means I'll 'leave out' or 'not say' a lot of other stuff I might say to a person with a very different personality. Or are they more apt to go off on tangents and speak broadly and philosophically and emotionally?? Well, I can *definitely* do that.

So I think it's more meeting the other person at their level of being - and in that moment in time.
Or as a child, not rebelling against my parents because it didn't occur to me to do otherwise -- just putting their feelings ahead of my own, and valuing their needs higher than mine. Not wanting them to experience negative emotions as a result of something I did. Not wanting to cause problems. (this is just a generality -- over time there's more of a balance for me - i.e. my needs vs. the other persons -- but yeah, Fe for me tends to be putting the other persons' needs ahead of my own, whether in a simple everyday conversation, or something larger - and accommodating my delivery or expressions accordingly - because it makes me happy when other people are happy, and I want to add fuel to other peoples' joy if they're joyful, or if other people are sad, I want to explore those feelings with them to help them gain peace or clarity....just to understand them in that moment in time).
For me it's really getting to know the other person, learning about their needs/behaviors, and adjusting my style if necessary to accommodate their needs. I don't view it as being 'fake' at all, as I'm still fully myself; this is who I am. And those I have deeper connections with will in turn see more sides of me. If I sense that they're uncomfortable and need reassurance on something that they're saying -- like if I sense they lack confidence or are hesitant to speak their mind, then I will be sure to smile and give them a verbal pat on the back, and be more encouraging in my mannerisms and responses, so that they feel safe to be open with me. But I never push people towards doing anything or saying anything -- if I sense reticence, I don't push for anything. I want people to be fully themselves and I don't want to influence them otherwise. And perhaps the Fe is more of a 'tool' that I use to connect with others because I want to create a 'safe' environment where they can be authentic and REAL. Actually as I'm typing all of this out, I think it boils down to simply validating their feelings and experiences, whatever they are, and trying to understand them.
This might be just me...so I tend to hesitate about posting stuff like this because I don't really want to speak for everyone out there who might experience completely different things when it comes to Fe.
Edit: I also tend to think manifestations of Fe will vary between personality types, especially between your I's and E's. For example, my Fe is going to be rather different from ESFJ's Fe, or ENFJ's Fe, or...etc.. and I'm not certain it is approached in the same matter internally, even though externally it might look the same.
Edit2

: And sure, Fe is also about what's 'appropriate' in a given situation or in the group setting/culture that I'm in - but that's just the icing. All of the above is Fe on the individual level.