More training and development programs
Effective communication. Create an inclusive and honest atmosphere.
Provide more competency based training to influencers and target those who abuse their status as manager. Establish a complaint system; monitor areas of turnover; reward good managers based not on their performance achievements but for what they do interpersonally; 360 reviews.
Grad students support could have been better, especially regarding the prof-student relationship. The profs are too secure that there is no motivation for them to improve their attitude.