Just be aware, it's not movement (in space, external) here that's being looked at. Like Cady said, it is intent, that happens solely within the body-mind before any external movement has been involved. And the fact that it is called "6 directions" does not even mean that those are the lines we are actually initially working with, think of it just as a descriptive allusion, i.e. the cross-lines of fascia through the body, motivated with intent, can effect horizontal and vertical stability and are initially more important than any lines that would actually run horizontal on some imaginary 6 direction compass.
I have always followed the idea that in essence, everything is really quite simple. If something seems difficult, it is simply because you can't see it yet. If people make things complicated, it means either: they do not understand, or, they are trying to complicate things for no reason. Everything should be simple.