For your feature meetings the recipe for success is the same as any meetings, have an agenda and other materials people need to review before the meeting to be prepared to contribute without wasting everyone’s time, and take minutes and distribute them after the meeting, the minutes document the decisions made so they don’t need to be rehashed on the next meeting, and the minutes feed in to the preparation package for the next meeting. It is a lot of work to prepare these meetings and keep them on track, on the agenda items, so that the required decisions get made.