Are the players working on their hitting outside of team practices? Hitting is a skill that must be relentlessly developed and maintained.
Also, look to improve the quality of reps. Mindless tee swings on a ball right in the middle of the zone isn't going to do much. If you need to use a tee, attach a specific goal to the work (for example - set it up on the low/out corner, and have them work on driving that location hard).
Have regular team discussions on mental approach, and learning how to adjust their approach depending on the count.
Also, look to improve the quality of reps. Mindless tee swings on a ball right in the middle of the zone isn't going to do much. If you need to use a tee, attach a specific goal to the work (for example - set it up on the low/out corner, and have them work on driving that location hard).
Have regular team discussions on mental approach, and learning how to adjust their approach depending on the count.