Try these two youth baseball practice drills to help you assess your players skills at the start of the season and then to help them with their fielding and throwing skills in a short 15 minute drill.The first drill is a throwing drill that I use to assess my team. I call it Face the Base.   The second drill is a simple, multi-purpose drills that gives them fielding and hitting work in a short time.

Face the Base
I hang the bases on the backstop and use them as a target for the kids to throw to.   It really helps us look as they throw the ball to see what they need to improve on.
At the end of their throwing motion I would have them Face the Base to complete their motion.

Fielding and Hitting Drill
This is a simple drill, but allows players to get a lot of fielding and even some hitting work over a short period of time.
You have 3 players per group; a hitter, a tosser, and a fielder.
The fielder should stand about 30-40 feet away from the hitter.
The hitter chokes up and uses a short swing.
The tosser, kneels and tosses balls to the hitter from the side.

As soon as the hitter hits one ball, he qucikly resets, and the next ball is tossed.   The fielder must field the ball, toss it to the side and quickly get ready for the next one. After all balls have been hit, players switch places.

This drill can be run for 15 minutes or coach can set a certain number of rounds.