1. What is your audience interested in?
2. Has the topic already been written about? NO, then you are good to go.
3. Has it already been written about but with room for improvement?
4. What if no single blog paints a complete picture of the topic?
5. On the other hand, if others have already nailed it, don’t try to compete.
Essentially, you need to add value to the ecosystem. You want to make sure that you are speaking directly to your audience’s distinct and current interest, right where it intersects with your particular expertise, and that you are saying something that hasn’t already been said, in a way that adds more value to your audience than what is currently available on the subject.