Make sure you have a designated media contact person. This should be the individual whose name and phone number or email address appears on all the "Get More Info" paperwork. This is the person who should be taking care of getting the word out to the local Pagan community. However, because this will also be the person who may end up talking to the press, make sure it's someone who's comfortable with public speaking and who will represent your Pagan community in the way you want the public to see you. Go for outgoing and friendly over taciturn and moody.
Your communications team should make a point of getting posters and flyers out into the community well in advance of the event. They should be visiting local Pagan businesses -- and non-Pagan businesses that have a Pagan clientele -- and talking up the event. Social networking sites such as Facebook and Meetup are a great way to get the word out to people who might not otherwise be aware of your event.