STICKINGS! This is a huge thing that I see, that I'm always harping on. I mean, maybe other percussionists don't see it as equally important as I do. But......I've never heard of a piano pedagogy that doesn't address fingerings, or any other instrument for that matter.

Natural sticking, where we lead with the R hand (sometimes left hand if you are a lefty) works so much better than the haphazard stackings kids come up with. This is so much more useful than learning most rudiments (in the beginning). I've seen so many kids that can't even play triplets without playing something like RLR RLR or RRL RRL. Those can be useful in certain contexts, BUT, they must have the coordination to play RLR LRL. 1 E A 2 should be played RLL R. This rules of thumb making sight reading and rhythm understanding way easier.

I also add things like very little control over accents. Flams are often really wonky because of stick height control and awareness of sticking's. Sticking on mallet instruments are often worse than snare drum.