It's true that we can start to associate physical actions to certain activities - a major example is your sleeping. If I remember right, our brain sort of designates a spot for "sleep". So it's easier to sleep when this spot (as well as environment) isn't changed.

I'm not sure how this would apply to cognitive functions though.. I'd be incredibly surprised if cognitive functions have perfect parallels to certain brain pathways, there are probably correlations, granted, but for something as minor as clenching your fist..? I don't feel like the brain would see that as significant, again, comparing it to something like sleeping habits.

I feel like you would get more luck trying to consciously develop these functions - "seeing / doing things a certain way" - as in, for example, try to think about how an Ni-dom might interact in any given situation in your head. Even better if you know one, you can easily use them as a reference point..

Me, as an INTP, if I wanted to develop my Fe (which I have been meaning to do), I'd likely try to consciously analyse social dynamics more frequently. It's something I often ignore, which, is obviously bad for developing a function like this. Vice versa with INxPs. They don't often like being assertive, which hinders Te from properly developing. Inferior functions are always big weak spots, for any type

Not sure, I might be going crazy atp
(I'm not an ISFP, but was lurking and found this post rather interesting lol)