Last year I decided to do a drill with my 7 — 9 yr olds who had a hard time catching the ball properly. Using this technique my players really improved their catching skills.

Catching Drill for Youth Players
What I did was purchase the round Velcro padded mitt with a tennis ball type ball, and made my kids get on their knees.   They were forced to get their catching hand in the proper position, palm always out, not up.

I would start by throwing straight at their chest, then throw to opposite shoulders.   After doing this drill with them each practice, I noticed a big difference in how they started catching the ball.

The reason for them to get on their knees was mainly two reasons.
One–they still had the tendencies to “underhand “catch the ball above their chest when standing, and by putting them on their knees they for some reason stopped.
Two–it kept them in one location and not running around everywhere to help speed up practice.