Comment by kurthr

That's about the right size for a potluck. Set a rough guide for the main and have people post what they're bringing. If they're good friends they'll put their dishes in the washer/sink and some will help clean before they leave. If they aren't good guests (bring something + fun + clean up) they don't get invited back. Have it once a month on the same day. Plan to rotate it and talk about it at the party.

Of course people have all sorts of different ideas of what a party should be, what to bring, and what to do while you're there, but doing it all yourself is really hard. If you're getting it catered with cleaning staff, it's very different than having mostly the same close friends, month after month year after year.