After work, casual, CBD-based meetups with a specific theme seems to work well for us. We usually try and make sure there is a clear benefit for being there - get personal feedback, get explicit pointers on a particular thing, meet and speak with a particular person, compare/chat about a topic in a structured setting, etc.
We have a regular place we meet, but if going to a new place we scout it out in advance and speak to the manager to ensure they know to expect us. They're often happy to reserve an area for us.
Also a good idea to print out some A4 or A5 signs you can put prominently in a menu holder so people can see where you are from a distance, or wear t-shirts/hats they can recognise. Being friendly to anyone wandering over towards us prevents awkwardness and makes people feel welcome, and we intentionally try and match people up by introducing them to others with a common interest.
We start off just letting people chat, and then might move into something a little more structured (but still casual) as this is often where we can help create value from the people coming together.
Oh, and we often order a couple of bowls of wedges/fries/nibbles etc to share around the tables so people have something to munch on. You can also clarify with attendees at the beginning (during a housekeeping speie) about food/meals also being available as often people are having such a good chat that they have talked for hours and miss out on proper food because the kitchen has closed!
Fire through any questions you have and we'll see if we can help with them too.