Find a place to throw
It’s still a little early to think about throwing a ball, but it’ll be January before you know it! And if you’re somewhat serious about starting early, you could find a gym and start throwing indoors.
Throwing correctly is one of the most important things to teach kids. Turning your body and pointing at your target with your glove hand will get them off to a good start.
A good drill that keeps things moving is “Rapid Fire”. Have the kids line up to the side about 30 feet away. Start out slow. Have each kid jump out from the line and throw them the ball. They should execute the correct turn, point and fire back to you and return to the end of the line. The next kid jumps out and so on. You can really keep things moving with some rapid throws. Mix in some ground balls and fly balls and you’ve got them warm and loose. You can back up a little as you go as well, making the throws longer. Stress the fundamentals of a good form and accuracy. I would end the drill by moving all the way in and “underhanding” it like an infielder, sometimes throwing it behind our backs to mix in some fun.
Kids need to throw more and they need to make longer throws. This develops arm strength and accuracy.
Remember, keep it quick and fun, and teach them something.