What's your technique for coming up with cool topics to blog about?

Strategies that worked for my blog are :

1. Joining communities and observe what problems people are talking . Then write an article for that.
2. Twitter threads. Recently twitter has been crazy about threads. If you look at them they are almost like blog posts. Read and improvise and publish your own flavor.
   This is how I recently came up with bunch of working ideas at http://tipseason.com/

I don't know if this is golden, but I'm trying out James Altucher's technique of coming up with 10 ideas every day (Idea Machine). https://jamesaltucher.com/blog/the-ultimate-guide-for-becoming-an-idea-machine/