The first paragraph should deliver on the headline. Start with a question, a statistic, a provocative statement or a powerful benefit. Subsequent paragraphs back up the first by providing background information, quotes, and other relevant details. Keep it to about one page. Make it timely.
Media love something new and they also love tie-ins to events, holidays, other news stories, etc.
Make it accurate. If there are typos and misspellings in your release, it will get tossed. Make sure phone numbers, dates and addresses are correct. If they can't trust it, they won't run it. Make it easy to read.