There are lots of things that make an effective team, but one of the most important, I’ve found, is to make sure they have a clear and meaningful goal.
Part of this is to separate the goal (or the benefit, or the value) from the way they’ll achieve it (the solution), and then make them responsible for the achieving the goal, not for delivering specific parts of the solution.
This way our teams—particularly product or project teams—can be more flexible and more responsible for their success. They have the freedom to come up with solutions, and prioritise actions that will achieve the end goal. Moreover they also have the responsibility to come up with appropriate solutions, because they are accountable for the effectiveness of the solutions they choose.
In contrast, a team which is given a solution, or a number of specific deliverables, is not accountable for the effectiveness of them. That responsibility lies with whoever planned the solution. But if the solution isn’t effective then the planner in turn can easily blame the delivery team for not producing the thing in the right way.
The team can be further accountable if we don’t express the goal in black and white terms, but rather make it something which can be expressed as “more or less of something”. (E.g. more confidence, less delay, etc.) That way they can further be expected to demonstrate continually increasing value—partial value from partial delivery.
But it all starts from first ensuring they are responsible for delivering clear value.