Yeah, we're (HS) pretty conventional with our pitching and hitting instruction. For P's, live down and away but come up occasionally to change the sightlines and/or get a chase. Similarly, you have to be willing to work in sometimes to keep the hitter from cheating out to your target zone. Our HC/PC does a great job but likes to come in on 0-2 and I don't like that risk in that count. Also, in HS, I think it's fine to work the middle when pitching backwards to get ahead. This also helps the effectiveness of those off-speed pitches when you later start them in the zone and drop them down or out.
Of course, know your hitters. If they can't catch up, don't help. And many lower order kids can't stand in on a righty/righty or lefty/lefty hook.
As a hitting coach, we work oppo a LOT. Eliminate holes in the swing to reduce vulnerable pitch locations. Know the pitcher's purpose and use it to your advantage. When 0-2, 1-2, get on top of the plate. Put some of the pressure back on the P, daring him to come in, risking hitting you, and assuring that outside is outside.
Similarly, know your strengths and weaknesses. If you are not a cerebral player, go look for a good pitch and drive it.
Back to pitching, I'd say the majority of our P's get to the point where they can work down pretty well. I don't know too many who are able to live down that don't have success, even if they can't hit other locations very well. Not surprisingly, some of the guys who really thrive on living down have a hard time getting that occasional "up" pitch up enough. Ouch.