The Three Amigos

We followed a similar process when I worked at Intelliware.

Before commencing work on a feature, the team would gather around the whiteboard and discuss the intent of feature, and list out the tasks required to implement it.

An estimate was added to each task, and summed up to provide an overall estimate for the feature.

Involving the entire team (BAs, devs, QAs, PMs) meant that everyone knew what was going on, and often surfaced ways to leverage existing components. It also helped to avoid conflicts between features impacting the same parts of the codebase.