3 plate front toss. Plates are lined up vertically with about 2-3 feet spacing. Have the slapper alternate hitting at each plate which helps them adjust timing. When they get good at that, then begin to vary the speed of the front toss pitch as well to add more timing challenge. I like this drill because it's easy to set up, can be done in a cage, and is easily integrated into the practice session.
Don’t start moving until ball is about to be released. All hitters, slappers included must time their movements with the pitchers movement. Slower pitchers move later, faster pitchers move earlier