When George Will began his career as a syndicated columnist, he asked his editor William Buckley how he could ever come up with two columns per week. Buckley replied that at least twice a week something would annoy him [Will], and he just needed to write about it.
I don’t write about what I find annoying, but rather what I find interesting. I’m always running into things I find interesting, and sometimes I write about them.
One strategy for coming up with ideas for blog posts is to fill in details from your reading. I’ve done this several times lately. And many of my programming posts come from my research to fill in gaps or resolve ambiguity in software documentation. You can also subtract detail, i.e. write summaries, but posts that add detail are likely to be more original.
It’s somewhat easier to be perpetually annoyed than to be perpetually interested, and so it’s a somewhat easier route to sustaining a writing pace. The flip side as I see it is that the former is much more like an addiction than the latter.