A theme night at a club can become a favorite weekend outing for partiers. Sports themes are particularly useful, because there is no time of year when a sporting event isn't happening. Have people come in their most outrageous fan gear for the local team. Other classic themes are angels and devils, with matching themed drinks for each side, and an '80s night, which gives patrons the opportunity to break out the acid wash jeans and leg warmers. Be creative though. If there's something that you think will be a better draw to your specific clientele, use it.
A concert night can be a good change of pace from the typical nightclub scene. Depending on the size and location of your venue, you might choose to spend some money to get a well-known act for a show, or highlight some exciting local bands.
In a similar vein, a big name disc jockey will pack the place any night of the week, but a DJ contest is a cheaper, potentially more fun and interactive experience for club patrons. You can give out a prize to the DJ who wins based on crowd response. Having competing DJs means that you will not have to pay as much, and you might discover someone whom people will want to come back to see on a regular basis.
The oldest and best way to get people to your establishment is a good special. Half-priced well drink night or a few dollars off of a particular brand of beer might seem obvious, but depending on the night of the week and the surrounding club scene, a good special might bring the entire night's crowd to you. Again, be creative with your specials in a way that stirs up people.
With all of the networking options out there today, there's no excuse for people not knowing about your promotional events. Start Facebook groups and e-mail lists to spread the word about your events. These marketing tools are free and effective, and they give you more flexibility than handing out promotional cards or airing radio ads.