Good editors have a feel for the interests of their audiences, and in many cases readership research has helped to clarify those interests. In other words, tone. The number of people affected by an event is often critical in determining how extensively an account of it will be read. If garbage rates are to increase throughout the city, the story has more impact than if the garbage rates of only 15 families were affected. If the event happened nearby, it may be more interesting to a newspaper's readers than it would be if it happened in another country.
News is important when it happens, and old news is of little value to readers.
Prominent people are of more interest than those who are not. If the president changes his hairstyle, that may be news. If the local butcher does, chances are that few people care. A 30-pound tomato may be interesting, and therefore newsworthy, because such a tomato is unusual. Events that are firsts or lasts, and therefore historical, also may be unusual enough to merit attention in the news.