Q: How does one stop a person starting the meeting with windbaggery?

A: Much the same as you would at any time during a meeting. It would help if you set expectations or ground rules about being concise and staying on topic at the start of the meeting.

If someone starts going on for too long, it’s usually best to be fairly direct and say something like “OK, I understand, let’s hear what xxxx thinks” or “That’s great, what does everyone else think?”, or if the speaker is going off topic “Can we get back to the agenda and if there’s time at the end we can discuss this point then”.