Here is a great book on the subject: https://smile.amazon.com/First-Break-All-Rules-Differently/d...
Essentially, great managers do these things:
- Create clarity - Provide support and equipment - Celebrate wins - Build an atmosphere of learning and development - Help cultivate personal connections - Give developers the space to work in their strongest areas - Listen to the opinions of the members on the team and make sure they matter - Instill purpose - Practice empathy - Commit to quality