Post retractions. When you disseminate false information, own up to it.
A good example would be the Andrew Garfield/Batkid story. One day you suggest he's a horrible person by picking up a newsfeed from other sources. The next, you say that the story was incorrect- but you downplay your own role as a media outlet in spreading the lie.
If you aren't going to fact check so that you don't fall behind trending stories, at least take your share of the blame when you spread misinformation that can damage someone's career.
Your retraction should be just as big and bold as your initially-incorrect story.