Effective headlines are short. They use them because peoples attention span is generally short, sound bites are memorable. A good headline is like a good sound bite, short and memorable. To shorten your headlines, eliminate adverbs and adjectives, save them for the ad copy where they can be justified. This will also help eliminate some of the sensationalism, making your headline more believable.
Effective headlines are easy to read.
When typesetting your headlines don't use flowery fonts, reverse type, all caps or italics. Many people find these difficult to read and will skip them entirely. Again, you don't have to believe me, look at your local newspaper. Chance are good they utilize a simple, easy to read type style such as Times Roman. Headlines that stir the emotions will make more sales.