Colored wiffle balls - Off-Speed Drill
Buy red, white and blue wiffle balls. The plan is to train the hitter to see the ball better and that will mean longer (essential skills for hitting off-speed pitches) Inform the hitter that the red ball is to be hit hard to the correct spot (inside pitches are pulled, etc). The blue ball is to be bunted and the white ball is a take.
I think you will be surprised at pitch recognition after only 4-5 practices.
This is also a good indoor practice.