Over the years my wife and I inherited the running of several clubs and they ran with varying degrees of success
We finally decided to start a new club and found that our formula was successful, in as much that when we passed in on the a new organiser he had a bank balance to play with.
We started on a Friday night at 8.30, we started even if the room only had a scattering of people, the audience very quickly understood that if they were not there at 8.30 they would miss out.
We accepted 5 singers per week who got in free, after that EVERY paid, even if a well known "turn" came in they would be asked to pay.
We had a guest each week, trad one week, contempary the next, and tried to get a humerous act the third, although this wasn't always possible.
Two singers, two songs to start the night, followed by Artiste, then a break were we sold raffle tickets, badges of the club, told people what was happending in the near furture and TALKED to people, it is vital people feel part of the club, if anyone new appeared my wife would attract me and I would introduce myself, take them to the bar, buy then a pint and sit them with someone I could rely on to teach them the etiquette of the club, basically no walking or talking while someone is singing.
The second half would have 3 singers doing 2 numbers or 2 doing 3 followed by the guest.
I also wrote a column for the local paper, were astonishly good reports were filed every week .............amazin' :-)
It worked very well even though I say it myself, the room looked full with 30 people in, every week we had 50-60 crambed in, it seemed to suggest a succesful club and because it suggested it more people came having been told about this wonderful club by their friends

Good Luck, hope you can pick something useful out of this