You can only teach young, fit players who are trying to make it in tennis.
Old farts can't hit every ball hard.
And you will kill the rotator cuff in most of your students in a short time.
I"d back off that statement about "ripping" every rallyball as hard as you can swing, but aim to a safer spot idea. That is really blind tennis.
Even in young, fit, athletic kids, some rip like Courier, but other's message and feel like Gilbert, Rios, and Mecir.
Don't make the mistake of insisting every player has the same mentality or physical determination to just rip the ball every time.
I know the idea of simply swing hard and getting it in sounds romantic and a reachable goal, but it really is a fantasy for most players.
This coming from an old fart with rotator cuff problems on both shoulders and no ability to run.