These ideas on [tag]softball coaching drills[/tag] come courtesy of Chris and Eileen.  Softball Coaching Drills

Chris says to try this for [tag]softball[/tag] players who tend to have long swings.
Place a Bath Towel across their chest and have them hold the bath towel under their arm pits.   They are they then to take a swing with full extension through the ball only letting the towel fall after impact and extension through the ball.   Promotes a compact swing and a proper wrist release.
You can do this during any single tee or two tee softball [tag]drill[/tag], to help with inside and outside pitches, soft-toss or any [tag]batting[/tag] drill period.   This is a cheap and easy way to promote a more compact swing.
From Eileen…

It’s fun, messy, and helps develop soft hands.   I have my girls pair off facing each other.   They start fairly close together and toss an egg back and forth — moving a step back each time they successfully complete a set (one toss and one catch each.)  
After the eggs, bring out the water balloons and have them toss those — it helps clean up the egg!