Are you on meetup.com? You can get some great ideas by looking at what other groups all around the world are doing by looking there.
Here in Austin, the organizers have meetups in their back yard which is quite large and fenced. Music is played in the background (but not very loud) and there is always a cooler with drinks, as well as many bowls of water for pups. There's usually a table set up where you can find information about local dog "stuff" as well as doggie clean-up bags and things people might need while they're there. We just bring chairs and blankets, sit around and chat and watch and play with our dogs. Some people bring treats for the dogs and others swap stories of trainers and places in town that others should know about. It's very laid back and comfortable.