After the meeting, visit with the new people and actively solicit their feedback on what they enjoyed about the meeting. People are usually very polite as newcomers and sometimes you have to gently push, asking specific questions about what they learned or enjoyed and if they intend to come back. An observer's first view of an object is a very special truth, one that the experienced observer may have forgotten. Visit meetings of other clubs, astronomical or not. If you live in a large metropolitan area, you may have other local astronomy clubs in the area to visit and there is probably some of your membership that regularly attends those meetings.
Many clubs post their meeting information on the Internet as well.
Document the purpose of the regular club meeting. Take pencil or keyboard in hand and write it out for yourself. Do it right now and then discuss it at the next board meeting or club elders' pizza dinner. If your club has documented mission and goal statements, start with those. Generate enthusiasm and support for organization projects.