Headlines are usually the first thing a potential reade, linker or search engine will see when looking at your content. It is the first opportunity to capture them. A headline needs to be descriptive, memorable, to the point and unique. These are not always things that work together well.
A factor to consider is that many search engines are not as smart as readers for parsing headlines. The New York Times reports:
A common practice is to write articles specifically designed to encourage linking. This is known as linkbait. Headlines for these articles matter a lot. Here are 10 Sure-Fire Headline Formulas That Work
People respond to visuals. Text is good, but pictures and moving images can explain so much more. Make an effort to put an image in every post that you write. Here are some great resources for pictures or media that are generally free:
It is generally also considered OK to use a photograph from another site, even if copyrighted, so long as that photo is dealing with the same story and is attributed.
See also:
Andy Hagans’ Ultimate Guide to Linkbaiting and Social Media Marketing