Ever notice how the ones with family in the trade pick up the taping rhythm faster? The muscle memory is already there. My best tip is to put a fresh blade in their knife and a small hawk in their hands on day one. Let them get the feel of the mud itself, even if it's just practicing spreading on some scraps. That early comfort with the tools sticks way more than just watching someone do it.
Read somewhere that handling the tools first builds nerve memory before technique even matters. @the_ray wondering if it helped by lunch kinda proves the point, right? Just gotta get the mud in your hands.