@RiverRat and
@ballmachineguy
Sometimes you run into players who want instruction but who have little coordination and less self-awareness. A side by side video comparison of the player and a similar pro can reveal things to both coach and player.
Also, sometimes you have to give instructions that make no sense out of context. You might be asking for the player to tilt his shoulders, knowing if he does, the rest of the body assumes the archer's bow position, but the player may not respond to that specific instruction. Maybe that player
will respond to the instruction of sticking their hip over the baseline.
Sometimes you just need to reword your instruction until it clicks with the student.
Finally, remember that new movements are awkward. (Try throwing a football or serving with the off-hand if you've never done it before) you have to consciously and mechanically practice those movements until you build the new muscle memory and it becomes fluid and natural.