Lots of people will tell you to start a content site in a popular market, or something that you’ve identified a gap in.
Let me be a contrarian and tell you that it’s really all about passion. Sounds cliche, but I’d personally not have it any other way.
Passion plays 🙌
My personal ‘passion play’ was a niche/industry that I’d lived and breathed already for 8 years.
And something that I was a part of for a long time before that.
Your mileage may vary, but that’s been my experience.