I have a drill that has worked well for my players since [tag]coaching girls softball[/tag]. It helps them in their decisions to steal 3rd base.
This [tag]softball drill[/tag] requires a pitcher, catcher, shortstop and 3rd baseman. The remaining girls line up on 2nd base and take their turn as a baserunner. The pitcher pitches the [tag]softball[/tag] and the baserunner takes a big lead. The catcher then throws the ball back to the pitcher and the baserunner makes a decision to run back to 2nd base or steal 3rd base. The girls have learned how much of a lead they can take without getting thrown out in a game situation. 
The drill teaches the girls to be more aggressive stealing bases in the game and also keeps my pitcher alert to the opposing baserunner’s positioning to steal.
We have had good results in games and the girls have become more confident stealing 3rd base.