The creation of fake news is not the core problem – lying has been around for as long as people have spoken (“Thou shalt not bear false witness,” the Bible says). The problem on social media is that people who don’t know better spread the lies – and the technology enables them to do so faster than ever before. Like the difference between a fire on someone’s stove and a forest fire burning thousands of acres, virality is the primary issue, not the original lie.

Source: Stopping Fake News On Facebook Is Actually Simple. Here Is How I Have Been Doing It For Years.
I try to follow my own rule: On Facebook, I share items I create, or links to items I have created – rather than links to sources whose authenticity is hard to gauge.
I unfollow or unfriend people who frequently share fake news. By breaking the link, fake news fails to achieve market share, fails to go viral, and will not make money by selling eyeballs to advertisers, which is the goal of the fake news publishers.
Propagandists play the same game too – exaggerated or false headlines designed to grab our emotions, which we quickly Like and Share without a moment’s thought. Social media propaganda and fake news use the same methods – don’t play the game!