A basic building block of a media relations strategy, press releases should be direct and concise. After opening with a headline that makes clear what will follow, they should not exceed a page.
When writing a press release, consider the fact that it will be one of many to cross the desks of those who consume such things. As such, you need to consider what you can do to pique the interest of and provide value to such individuals. Finding an interesting and valuable angle increases the likelihood that your reader will follow up and report on the topic of your press release.