This is where coaches and pitching coaches see things differently...
Buy the ball on the stick or make one.
As a PC my main things I obsess with over my pitchers are Mechanics and Control.
As those improve and I introduce breaking pitches, "spin" becomes another things I obsess about "a little".
It's a component of pitching that fascinates me and I want my students to feel the same I do.
We do spend a lot of time in class spinning.
I encourage all my pitchers to be in the 20's by high school.
In high school I ask them to work hard to get to the magical 100.--All 4 spins added together to equal 100.
I have one at 110 right now, and another 2 hard workers at 96 & 91.
The highest spin is a rise at 29.3.
In class what we do is a lot of what I call "Super Spins". Basically off speed 1/2 step pitches with main focus on spin only. I will also use a lighter ball sometimes, which forces them to take the throw out of the pitch and put the spin in it. I'll use buckets as visuals to pitch into to help them see the spin and the location of the pitch.
I also take the fear away and allow them to just spin and not harp on location/speed. We end up training that back as the spin improves.
You can't make a kid spin well if they are not willing to put the time into it. Constant encouragement is and a willing participant is the best you can do.
They really are worth the investment.
Had a young lady entering 8th grade visit this last week, and with a few tweaks, she was spinning beautifully. I was blown away by her spin of 27+rps... a very high rate for someone that age. It really helped validate the hard work that they've put in.