You don't need to be a rocket scientist to write a great press release that's just about guaranteed to get your event covered by the media. Needless to say, it must be an event or gathering worthy of professional coverage.
The easiest way to publicize is by writing a simple, one-page release. You need to list
WHO / WHAT
WHEN (specific day and time)
WHERE (exact location, w/directions from all points unless it's a well-known location or landmark)
People to Contact BY PHONE
Email addresses are optional
You can put everything above in crayon on a paper grocery bag: the most important thing is to have LIVE people waiting to IMMEDIATELY answer the phone (or return calls ASAP) as well as someone manning the email account to answer inquiries IMMEDIATELY.
NOTHING ELSE MATTERS! If reporters or media outlets can't reach a live body for verification or clarification purposes, you don't have an event!
In my career as a journalist, I have seen this happen time and time again (most recently last week - I was the only reporter who showed up at an event because I was familiar with the location, and had nothing else going on at the time - prior to heading out I had made numerous phone calls to THREE numbers on the press release, EVERY SINGLE ONE was on Voice Mail, each having a vague message that would make you believe someone might get back to you WHO KNOWS WHEN!)
SEND your press release out on Friday morning if your event is on a Monday: send it out one day before the event takes place (email it out between 0800-0900) - EVERY TIME YOU SEND AN EMAIL OUT MAKE SURE PEOPLE ARE AT THEIR PHONES and / or READY TO IMMEDIATELY RESPOND TO EMAILS!