We ran our own mastermind group for over two and a half years, and are just about to pull the plug now. I know a lot of people who are surprised it lasted this long.
We met in person, face to face every month, and hired a meeting room for the purpose.
We never had a moderator, but the format was that each person had a whole hour to bring whatever problem or issue they wanted to share. They also filled everyone in on their last month at the start.
It worked incredibly well because (a) we were so incredibly different from each other in terms of skills, personalities and businesses, (b) we had very clear ground rules (eg: no checking email or anything during someone else’s session), © we always had lunch together so got to know each other personally. Also (d) there were no egos involved, so no-one tried to run it. And I suppose (e) we were very lucky with the personalities involved.
We also had weekly accountability in a closed facebook group which helped.
To be honest it was always a pain in the arse to take a whole day off for it, but I always walked away enthused, charged-up with some seriously good ideas.
I’m going to miss it terribly! We have our final meeting next month - and then we’re all staying overnight at a hotel for a Christmas meal. It’ll be great - but also a little sad I think.