One drill I do with younger boys just coming up from machine pitch to minors is line half my team at third base and half at first base.
I am standing at home plate rolling ball to my players at third. They have to charge the ball and field the ball (bare handed I might add) then make an overhand throw rolling the ball to the player at first base.
The player at first fields the ball in the same manner then makes a throw to my catcher at home.
This seems unorthodox to players on my team for the first time, but this teaches them to charge the ball and learn to field with both hands.
The kids I have on a regular basis have no problem with this and have developed great fielding skills with this drill. We go back to the basics at the beginning of each season because of new kids trying baseball for the first time.
For the little guys I stretch a rope on the ground using spikes. I throw them grounders working on their foot work. The first step is using their right foot stepping across the line, turning their foot 90 deg to pitching position throwing at the target. Gets them in position the throw the ball.