Coming up with a topic you actually care about is an important step because it will help you be interested in what you're writing about. The culture industry has a realm of things that could be written about, such as the impact of television on today's children vs. the impact of television on children who were born before the 2000s.
You could also look more closely at a social media platform and analyze how it's affecting teenagers and young adults. For example, consider Instagram. People are free to post photos and most often, they're photos that show the brighter points in someone's life—a great body, a partner, a vacation, etc. How does the way people present themselves in photos impact mental health? What negative consequences could be drawn from this type of social media platform?
Magazines, too, should be considered, as there are many different types that serve a different purpose. There are food magazines that give us healthy recipes and magazines for kids that teach them important values. But what about tabloids? What do those breed within our culture and how do they potentially affect the lives of the people being written about and given (often unwanted) attention?