Own your role
An important aspect of leadership is … leading. You may have aspired to a particular leadership role, or you may be strongly encouraged to assume that role, or you might even be forced into it through circumstance or “I guess I’m the only person who can do this now”.
Regardless of how you get there, once you are leading, others will follow better once you own your role.
Think of the times when you were not a leader, but were led. Did you prefer a leader who was wishy-washy or decisive? Reluctant or assertive?
This is not necessarily “fake it till you make it”, but is instead ownership of that role. You do not need to be arrogant, but it is important to acknowledge that you are leading so that you can behave like a leader and so that others can be more comfortable following.
What does that mean? “I am leading this effort, therefore I will take responsibility for making the final decision.”
Leaders can be effective in many ways, but the primary way is to simply be the person who is decisive. It is often more important that the team is on the same page, executing the same plan, achieving the same goal than that the goal is the right goal. Obviously, you want to pursue the right goal whenever possible, but it will sometimes be non-obvious what the “right” goal is and there might not be a consensus.
The blessing and burden of a leader is moving the team forward despite a lack of consensus.
So, once you are “The Leader”, lead.