I'm not one for having meetings just because there's supposed to be a meeting. There should be a purpose.
Now, that doesn't mean you want to overly plan every meeting. Sometimes you just need to get together as a group to talk, and you may not need an ultra-detailed agenda, because the point is to have some time to just see how everyone is doing.
But there are times where it's important to stick to working through specific problems and close out lingering issues. How do we know what type of meeting we're headed into? Well, we have an agenda.
Ideally, the agenda is sent out in advance, so everyone can prepare for it. This is important for the introverts, so they can think of what to say in advance and for the extroverts to have a chance to get past their knee-jerk reactions and filter themselves a little to what is most relevant to the discussion. Otherwise, the extroverts process out loud, while the introverts process silently, and by the time the introverts have decided what to say, the discussion has already taken place and we're on to the next topic.
In addition to publishing the agenda in advance, an important tool for facilitating discussion is called the parking lot. For those who have coworkers who like to hijack the agenda and take the meeting in a direction other than what we planned, the parking lot allows the meeting facilitator to acknowledge that there is further discussion that may need to happen on a different topic, while still keeping us on the published agenda topic.
The idea is that discussion circles around a given agenda item, and when someone mentions something that is off topic, no matter how important it may or may not be, the facilitator acknowledges the comment, thanks the commenter for it, and then either asks permission to place the comment/topic in the parking lot or just simply states that they are going to put it in the parking lot. Then, the important part, is that with a bit of a flourish, the facilitator writes it down. This can be on a white board up in front of the room or just on a piece of paper on the conference table or even a note window in a virtual meeting.
By acknowledging the off topic comment both verbally and in writing, there are two results. The first is that it is made clear that the agenda will not be hijacked and that particular line of conversation is over for the moment. The second is that it is made clear that you care about everyone's needs. Maybe that item will be on the agenda for next week's meeting. Maybe it will be taken care of in a one on one with just that person later. Maybe there will be a few minutes at the end of the planned discussion to circle back to it. Because it is written down, it won't be forgotten.