Research film festivals in your immediate area as they sometimes can be easier to enter if you are in residence. Film festivals usually have their own websites that give entry information.
Compile your film materials according to the festival's entry requirements, since the entrance requirements are often strict. Also, pay special attention to the film format of the festival. Some festivals only take digital entry while others prefer 35mm.
Be prepared to pay the entry fee. Most indie film festivals have fees that filmmakers are required to pay before their entrance is accepted.
Submit your indie film to the festival. Often times films have to be edited to a certain length to be considered valid for festivals. Big festivals like Cannes do often not have length requirements, but smaller ones tend to limit to 120-minute length film.