The great Camille Fournier has another blog post that is worth reading:
The managers who succeed in this may have big ideas about the technology, the product, and the talent and culture of the team, but they don’t just start with these ideas. Instead, they identify the little things that can be changed. Questions like “how do we decide what we’re working on today” and “do we have clear responsibilities for core tasks” start to get resolved. These managers may tackle confusing on-call schedules, or onerous project management expectations. The best will look across the projects and quickly re-prioritize work to gain focus for the team.
From The Management Flywheel