Your job is not to manage people. You read that right. Your job, like every other employee's job, is to improve the 4 factors critical to long term business success. Your job is to manage those factors. Not the people on your team.
The four factors of success
In no particular order, the health of a business is a combination of its:
Of these four, profitability is the easiest to measure. It also has the most immediate effect on a company. Because of this, the more abstract metrics: sustainability and morale, are often sacrificed in the name of improving profitability. This approach is shortsighted and bogus.
The best managers are the ones who recognize that high morale and sustainable workloads are key factors to achieving long term success. These managers don't spend their time managing a team in a traditional sense. Instead, they behave as mentors, encouragers, and work to find the ways they can best support their team.
Watch the product, not the worker
One of the biggest mistakes managers make is focusing on hours worked, or "face time" as i like to call it. These managers value butts in seats over work being completed. Of course this isn't exactly true: they in fact want both. Unfortunately, to a member of their team, the pattern will be clear: when you are not at your desk late enough, it is assumed you are not doing enough work. When you are at your desk more, even if you are doing nothing at all, managers will begin to sing your praises.
Herein lies the first lesson of being a great manager: watch the product not the worker. What does this mean? Judge a worker or team not by how they conform to how you work, but instead by their demonstrated ability to consistently get shit done on time and well. This seems like common sense, but in practice it can be harder than it sounds. Because just as profitability is easier to measure than morale, "hours at desk per day" is easier to measure than product advancement.
Your team is not a resource, you are
So if a manager's job is to watch the product and not the workers, how can they influence the pace of work being done? The answer is by improving efficiency of their team. There are a number of ways to do this, but the best is typically to act as a resource. People in managerial roles generally come with a deal of domain or product experience. Share these nuggets with your team to help keep them from going into a rabbit hole unaware.
It is also important to recognize the relationship between an employee's buy-in and their productivity. When a member of a team understands that the project they are doing is in line with their current interests, they get excited about their work. If there is an organic productivity boost bigger than a coder using a feature as a weekend hobby project, i haven't seen it.
Of course this is not something you can expect or even aim for, but it is something you can support. Understand what excites each member of your team. Learn their strengths and talk regularly to them about technologies or the side projects each is working on. Use this information as a factor in feature prioritization and assignment.
Be a shit umbrella
Finally, managers must understand their ears are a far greater asset than their eyes. It is well documented that CEO's are the last to learn things. What is often missed is that managers are the second to last. In order to keep a team of ever-changing people happy and challenged, you need to keep a regular pulse on the feels of the team, and the individuals. So talk to people regularly, both in group settings and individually. Keep it organic. Scheduled meetings add a degree of formality we have no interest in.
In these meetings ask what their ideas are. Ask for advice. Ask about what annoyed them about the feature decision the other day they were visibly upset by. Find out what they want changed and take steps to put the sensible ones into action.
Employees work best when they know a manager is on their side. Consistent communication helps to establish this rapport. But it is also critical to be their shit umbrella. What's this? Every manager is either a shit umbrella or a shit funnel. And no one likes being under a shit funnel. So in order to earn a team members trust, start by being on their side. Defend them selflessly. Shield them from the bureaucratic nonsense above. Find out what they want and help them get it.
As a manager, you may report to those "above" you, but you work for your team. Your job is to do what you can to make sure your team can do what it can.
So grab your umbrella, it may look like rain.