I was asked for some tips on how to start a tech blog like the one you are reading now.
I have replied with what I think is the most important thing to think about when formulating a post. And that is that your topic may be entirely new to your readers.
Another tip not mentioned in the article is what I call the “Work In Progress” post. This is where you simply report on what you have been doing. The absolute master of this is Simon Willison. I check his blog daily for new articles.