Well, one of the reasons that I participate so much in these Fe-Fi threads is that in teaching, I'm frequently dealing with immature Fi users and it's helpful to at least have an idea of what language is more effective for them. In my close personal life, there are a couple of cases of Fi users who are greatly impacting their kids by what they do/don't do, but I realize that anything I would naturally do to try to improve the situation is not going to be received as being loving. I care too much to just shrug my shoulders and walk away, so right now I'm kind of at an impasse.
That makes a lot of sense. When I was teaching, I had to learn to teach both in an Ni (here's how it all fits together) and an Si (here are the step-by-step repeatable instructions on how to solve a problem). The first thing I needed to do was drop the notion that there is something wrong with the step-by-step way. Physics is a very intuitive field, largely because there are only a few intuitive ideas to understand (the laws of physics), but a very large number of ways those ideas combine in specific cases for specific solutions/recipes. But that doesn't make the intuitive understanding "better", just easier. When running an experiment, all of those nitpicky details come to the fore and are more important than the simple theory(ies) being tested.
I would suggest that in your Fi-teaching case, the trick is realizing that the usual Fe-style motivators don't work: it's either going to bounce off of the Te as being unreasonable/illogical or off of the Fi as being too intrusive.
The Te is interested in "what works", so all of the extra fluff of why it's such a great idea to do whatever falls flat. It's enough that it works: that makes it a good idea. Te, especially in the Fi perspective, is how to handle all those things that one has to do that one would really rather not do. Emotion is detached, and you just do them. Sticking emotion context on them only confuses.
The Fi is where the motivation lies, but it comes from within, not from without. So you build motivation in Fi (in others) by allowing them to try and fail without fearing failure. Not that you coddle them - rather you can say things in a "harsher" way without emotion, pointing out what was done right and wrong, without any hint that one is displeased. That it's OK to fail, but one just keeps working at it. You teach them by letting them be themselves, within limits.
I'm trying to think how my favorite salsa instructor does it (ExFP). She just points out what I'm doing wrong by making it clear how to do it right, that it's just a matter of work and practice (Te), and mostly just letting me dance and letting her find things to improve.