Create a plan. You need to identify your audience and see how much time you can afford to spend on promoting this event. If you don’t have enough time, it might be better to ask someone else to do this part for you. Promoting the event is a very important part.
Create a Facebook event. Creating a Facebook event will also allow you to see how many people will attend your event, how many are still wondering if it’s a good idea, and how many of the invited ones won’t join it.
Post updates. Give the people all the information about the event. Of course, make it sound as good as possible. Post pictures, post all kinds of useful information. But remember, only useful information.
If they ask a question, any kind of question, reply. As fast as you can. This way you show them that you really care about this event.
Use hashtags. Always use hashtags. Both Twitter and Facebook allow you to use
hashtags to promote your event.