When you open up a news article in your browser, open a second, empty tab. Use that second window to look up claims, author credentials and organizations that you come across in the article.
Fake news spans across all kinds of media -- print\ and online articles, podcasts, videos, radio shows, even still images.
As Mad-Eye Moody said in Harry Potter and the Goblet of Fire, "Constant Vigilance!" Always be ready to fact check.
Even the best researchers will be fooled once in a while. If you find yourself fooled by a fake news story, use your experience as a learning tool.