What makes for a good meeting?

Reason

The most important thing about a meeting is the reason for your participation. If you don't have a good reason to be there, why are you wasting your time?

Agenda

There's nothing worse than a meeting that drags on and on, because nobody knows what the scope and outcome should be. Defining them is the essence of any good agenda.

Exchange

If a meeting is not a lively exchange of opinions and ideas, it better be an email instead, because again it's wasting everyone's time.

A good meeting should have a clear plan with an objective or goal in mind. It should also have an exact start time and end time. It should be well-organized, with all the necessary materials available for the participants to use during the meeting. Examples of meeting objectives:

• Brainstorm ideas to improve customer service levels.
• Select a few critical issues for discussion at this meeting.
• Discuss product development plans for the next three months.
• Develop a marketing strategy to increase sales in the coming year.

Lastly, a good meeting is something that can't be replaced with just an email.

Alex named the 3 key points already. Adding on top of that, I would say

Mind the timeslot

And remember your colleagues. Nobody will mind if you remember everybody 5 minutes before the scheduled meeting is over that it's time to wrap up. If there's still stuff to be discussed, propose a followup with a new agenda.

Keep it small

More people usually means more opinions. Depending on the audience, I'd

• Try and keep the meeting to 5 people max.
• If there are more people, ask them for questions and comments beforehand. Send out an agenda to the people. Like so, everybody is able to prepare themselves.

Don't brainstorm (in big groups)

Use breakout sessions instead. Even better: Use a proper technique. If you'd like to get creative, you could use the World Disney Method or Future Search

• An ice-breaker is always fun!
• A short introduction if not everyone is acquainted with each other.
• A meeting description. I want to know what the meeting is about before we start! I might need to prepare. This also helps people decided if they are needed at the meeting in the first place. Respecting people's time, essentially.
• If possible, an expected outcome. It doesn't have to be something grand like "solution to X" but "ideas for X" is much better than nothing. This sets expectations.
• 30-45 min meetings are the best
• If >1hr meeting, then a 5-10 min break is appreciated
• If a brain storm meeting, I like to start off by forcing my team to do some physical activity (waving arms, stretching, shaking booty etc.). It really helps!

In my opinion, a good meeting should:

• be short and precise. A meeting that drags on and on is just weary and boring. The agenda should focus on the problem or objective

• it should be lively. Honestly, a meeting that's too strict and formal makes me super tense. The coordinator should have some sense if humour

• there should be a sense if order. Too many people talking at once gives a good headache

• Meeting has a reason to exist, if nothing needs to be met about it gets canceled.
• Only people who need to attend are invited, everyone else is informed clearly about what matters to them.
• Clear who does what in terms of note taking, etc. (And thoughtfully decided upon beforehand, not just arbitrary volunteering)
• Finishes early if possible
• A fun icebreaker isn't so bad

This boils down either to reason or exchange. It's hard to imagine for more than a few people to have a valid reason to sit in one meeting, or a reasonable exchange that can happen between each of them.

Replace the meeting with something more effective.

In a sales context or as training, ok. but otherwise I don't
see what a meeting brings. And by meeting I mean personal
meetings with more than 2 individuals.

Turning on your video camera should be made optional.

15 - 30 mins max to the point and kept on track, ability to hang up or turn off camera