Put together a budget for your event which includes such costs as venue rental, ticket printing, flier design and insurance. You can earn back your costs through ticket sales, as long as you explain to your bands (or charity, in the case of a charitable event) that your costs will be deducted from the revenue earned.
Find local bands that might want to compete. If you don't have band contacts, you can contact artists through Facebook, Twitter or MySpace, or by attending local concerts. If you plan to offer a prize, mention this to the bands to encourage them to compete. Raising money for charity is also an incentive.
Find an appropriate venue. Inquire at bars, clubs and other concert venues. Some bowling alleys also host concerts. Find out where your participating bands have played and contact the venue owners. If you do not have access to live music equipment, choose a venue with a PA system. If possible, obtain a media kit from each band. Presenting these to club owners and concert promoters demonstrates professionalism.
Encourage the bands to sell tickets to their supporters. You can create and print custom tickets online.
Advertise your battle of the bands. Create an event listing on all of the major social networks, post an ad in online music classifieds, ask local radio stations to promote the event and inquire about posting fliers in the windows of local coffee shops, skateboard shops and other retail businesses.
Show up early and oversee the event, ensuring each band sticks to the performance schedule. You may need to recruit volunteers to help sell tickets, set up the equipment and for security. You can emcee the event yourself or hire a local celebrity, such as a radio deejay or seasoned musician.