I recently signed up for Reddit. During setup, I clicked on categories and topics of interest so the app could deliver relevant updates.

On the spot I had to decide my preferences: do I want ongoing content about this topic or that? Do I want them to send information about technology, politics, economics? Food, fitness, travel, entertainment?
Select Your Top Themes and Topics
I’ve had to do this several times over the years, with apps like Flipboard and most news outlets. I created my own categories for Twitter lists and Feedly subscriptions that groups the content by general topic.

The act of choosing—of being forced to choose—helps me make decisions. I must discern what I care to know more about and what’s less interesting to me.
Narrow Your Top Themes and Topics
Once the articles start flowing into one of these apps, filling my feed with content related to the areas I clicked on, I’ll often realize, “Oh, wait. Wait. I guess I don’t want to know that much about weight training or Broadway shows.” So I update my preferences, usually eliminating a category.

Before long, I not only realize I’m bored by topics I thought I’d like, I also begin to see topics I’m deeply interested in. When I stop everything to read an article and share it on social media, for example, or talk about it a lot at the dinner table, that’s a clue. I pay attention to my intensifying interest, as it's a strong indication it might be one of my top themes or topics.

We can figure out our interests in other ways, however.

What do you already know a lot about? Obviously, it’s been a topic of interest already.
What books do you check out at the library? That indicates you want to dig deeper and know more.
What outings do you invest time or money in? Do you often visit an art museum, movie theater, car show, live concert, lecture, conference, or state park? Our calendars and credit cards can point us toward our top interests.
Do you steer conversations toward a particular topic? Do you seek others who join you in an animated, energizing discussion? Take note. That’s probably a top theme or topic for you.
Where does your curiosity consistently carry you? You don’t have to be an expert to start digging into a topic that captivates you. Explore it.

When you begin to identify these top areas of interest, pick up on clues to narrow your focus. This will help you discover the kind of writing you can pursue.
Confirm Your Top Themes and Topics by Writing
To confirm which of these top themes and topics you want to write about—and the ones you want to be known for—start writing about them.

Did you…

read an article that riles you up? Write a response and submit it as an op-ed piece.
read an article that skims the surface of what you know to be true? Write a deeper and better-researched piece and submit it to a relevant publication or work it into a book.
read a short story that touches on themes you care about? Write something that grapples with the same theme using a different plot or cover the same theme in a different genre. Maybe you read a short story but you can explore it in a poem.
read a poem that stirs you with its subject matter or theme? Weave your own images or story into a form poem different from what you read, so you explore the same topic in a new way. Or you could switch genres and write an essay in response to the poem.

Whether you write nonfiction, fiction, or poetry, write to discover topics that captivate you, energize you, and hold your attention.
Your Personal Themes and Topics
The “subscription model” I talked about at the beginning where you identify top themes and topics will reveal a lot. But it leaves out something critical: personal history.

What do you obsess about from your past? What episode or memory do you return to in your writing to explore all over again? Discover that and you’ll further refine your top themes and topics, and kind of fold these obsessions into your top ...