Scratch your own itch with at least one side project
I try to work on one project at a time that scratches my own itch. Or, something that I want to exist in the world. An idea that keeps weighing on my mind until it is easier to do it than try to ignore it.
The side project might be one blog article, or a website, or a book. Whatever it is, create without the expectation of building an audience. Create for the sake of getting the idea out of your head and into the world. Make something you want to exist, then make it available to others.
If you keep building on the idea, it might just get you somewhere. By listening to feedback and making a few iterations, you might scratch someone else's itch. Or many people's. Or huge groups of people's.
And if it doesn't, that's fine too. You've left a mark and created something that you're happy exists in the world. That's more productive than a lot of what we spend time on.