One of my readers, Steve, actually suggested this idea for [tag]youth softball pitching drills[/tag]. Give it a try for quick results! 
From Steve…
Here’s a [tag]softball[/tag] [tag]drill[/tag] I use:
For Pitchers –“Handkerchief Reach” —
Have the pitchers do their normal [tag]pitching[/tag] motion, without any softballs.
While watching their mechanics, have a [tag]coach[/tag] see where their front foot (delivery) foot lands and where their delivery hand lands. Mark that spot.
Now take out a handkerchief (towel will do) and have the coach stand directly in front of the [tag]pitcher[/tag]. Tell the pitcher to do the pitching motion again, but this time to “hit” the handkerchief with their “pitching hand”. Repeat this activity, but each time, the coach moves a distance farther from the pitcher.
After about 2 -4 times, the pitcher has increased the “delivery distance” and “stretched further down/over”.
I have had pitchers add between 2 & 4 feet to their delivery motion and “end-up” distance. This has increased velocity, improved mechanics, etc.