Use social media. Twitter. Pinterest (okay. I'm not sure if that qualifies as social media, but still . . .). Instagram. And so on. I’m serious. It’s such a great teaching tool.
Why? Here are some ways.
Grammar. This one isn’t just limited to FB, though. Twitter is a great source for real-life grammar atrocities. Here is a developed that is solely devoted to grammar mistakes. Here are a couple classics.
Instead of (or addition to) having students do brain numbing grammar worksheets, they can search social media to find usage and punctuation errors. Of course, they will have to know plenty about grammar before they can actually find the errors, but once they have learned that, they can apply what they have learned to any social media outlet they want.