I agree with IMpossible, Don't be afraid to lose money in this business because it can be a huge payoff or a loss on investment. There are plenty of variables such as other events going on and of course the weather depending on where u live.
The method that Cyril gives is a much safer alternative to just throwing a party and hoping people show up. The method is leveraging college students that seem to be popular into selling the tickets to the event 6 weeks prior to the event. As long as the theme is good and you make sure that your team is working, you will have a successful event. Weekly events are a LOT more risky, U should be able to get a good thursday night special event as long as there are no better events going on, the weather is fair, and u build enough hype to the event.