CFOs and finance leaders, what do you think is the most important skill you should be focused on personally in order to avoid turnover on your team?

Communication is quite important. 
Ultimately, being able to communicate is the key part of leading a team especially as our roles change beyond the technical. 
The world is always uncertain - as leaders, whenever you walk into a room, your team will read your mood and your intentions. This is harder with some hybrid working arrangements. Being able to communicate effectively avoids any misconceptions in an uncertain operating environment. 
Lastly, research has shown that you have to communicate something 7 times for the communication to be effective. So very few people, especially busy leaders, would over communicate.

Exposure and horizontal growth. Project management and implementation involvement.Hands on learning that can translate into engagement and experience. 

Trust

Consistently show you trust your team and show your team they can trust you. 

Creating a motivating and learning environment with communication as a key element.