Make developers’ lives easier. Remove the crap that surrounds them on a daily basis so that they can get on with doing their jobs. Help out with the menial tasks, the documentation, the distractions and the unnecessary meetings.
Empower people, give them autonomy and the power to make meaningful decisions.
Promote quality code, quality tests and a collaborative, learning culture. Encourage experimentation and new technology when appropriate and keep existing code bases as current and up-to date as possible. No one likes working on legacy code.
Be open, honest and entirely transparent. Give feedback frequently, constructive criticism when needed and praise whenever possible. Say thank you, publicly and privately.
Allow personalities to shine, but be respectful of those who wish to keep quiet.