Co-hosted a local Bitcoin meetup like a decade ago, it was basically a local HN meetup as we ended up talking about HN and it turned out we were all active users :)
We had two different types of events, one which is the typical "Here is a person presenting, now you can ask question and later we all chat and drink beer", and the other more casual "lets just meet at this bar, order some food and see what happen", which I think worked out very well as long as you get some regulars you can semi-rely on.
