From Derek at Github

Team discusses:

In all cases, the exercise started with the product manager who was most in tune with why the team was formed giving the team that context.

This was mostly them saying why the team was formed and what they saw as the mission and vision.

People wrote down parts of that talk that resonated with them. We upvoted those statements and then started collaborative editing.

Vision went much the same way.

Values were proposed by everyone, voted on, combined, described, etc.

We've always done this remotely and mostly-synchronously. Last time I think I did it with two 1.5 hour meetings a few days apart.

We check in on mission, vision, and values every quarter to see if anything needs tweaking, if we need to be more accountable towards a value, etc.