1. Try a personal touch. Don’t just mass email all your friends. Talk to people in your immediate circle who might be interested and ask them to speak to their contacts. People are more likely to come if they’re being brought by a friend.
2. Have rules, but only a few. Establish an understanding about attendance, skill level and conduct. If you want to start a book club for PhD candidates, make sure that the slow reader in the group knows what he’s getting into. Don’t be too pushy, though. If someone couldn’t finish the book, don’t banish them from book club.
3. Don’t be a dictator. The club certainly won’t be fun if one person thinks they have more authority than everyone else. Be democratic, even if what you want to do isn’t what the majority wants to do.
4. Do be a leader. Walk the fine line between being overbearing and getting things done. In groups of people, it can be hard to get people to speak up and make decisions, set up meeting times and places. Be the one to send the proper emails, asking people to make their suggestions.
5. Rotate responsibility. People respond to being treated as resources. Let members organize meetings on a rotating basis, for example. If your movie club is seeing a film from Bulgaria and there is a Bulgarian in the group, ask them to lead the discussion.
6. Be an ice-breaker. Whether or not you’re the host, make sure that no newcomer feels unnoticed or unwelcomed. Get up and greet them the minute they come in the door and introduce them to everyone.
7. Touch base in between meetings. Start a Facebook page or a blog where members can share thoughts, links and joke around in between meetings. This keeps the momentum going and encourages friendship-building outside of the group’s primary activity.
8. Stick to the plan. If two out of five people suddenly can’t make the usual day, don’t change the day. They’ll be back next week. Continuity counts towards momentum.
9. Avoid drama. If there’s conflict between two members, don’t take sides. Ask the people involved to resolve their differences on their own. The club is not an opportunity for therapy. 
10. Encourage special events. Don’t be strictly business all the time. Make plans to have the next meeting at a new restaurant you all want to try. Or have a pot luck hosted by one of the members.