I don't think learning to write blog posts is particularly different from learning to write anything else. To the extent that that is true, I'd refer you to Stephen King's book On Writing[1]. Specifically, one bit of advice from that book (loosely paraphrased) "the best way to learn to write well is to read a lot and write a lot".
The other book I'd recommend is The Pyramid Principle[2] by Barbara Minto.
The sci-fi author Jerry Pournelle used to say that the first 1,000,000 words you write will not be very good. He was not alone:
> David Eddings, an American novelist who was most famous for his epic fantasy books, once gave the following advice to new writers:
> “My advice to the young writer is likely to be unpalatable in an age of instant successes and meteoric falls. I tell the neophyte: Write a million words–the absolute best you can write, then throw it all away and bravely turn your back on what you have written. At that point, you’re ready to begin.”
> That same advice has come from a number of other sources—it’s tough to determine just who said it first. Some point to legends such as Ray Bradbury or Jerry Pournelle, both of whom famously advice that new writers should write a million words before considering themselves ready to take up the cause.
Unless HN comments count towards the 1e6, I need to get cracking. I don't know my word count for blog / technical stuff, but I'm reasonably sure it's nowhere near a million.
While I and many others have issues with King's apparent inability to end a story and his editors' not saying "no" enough, one thing I have actively noticed in his writing is that I never get hung up on overuse specific words or phrases. For a counter example, Frank Herbert's earlier works had the phrase "shoots a glance" so many times that I ended up being focused on counting those rather than the story. I also tend to notice when an author uses a specific term more than their peers, such as Dan Simmons and his use of) "lapiz lazuli" rather than just saying "blue". It's fine to use, but it stands out to me in ways that cause me to pause my reading and acknowledge the term consciously, rather than keep the narrative flow in my head.
The first part of "On Writing" is fantastic, in the sense that it tells you through King's own life that there are no shortcuts: you must learn by writing. And sometimes, you'll have people to criticize what you wrote, and that'll be the best thing.
The other book I'd recommend is The Pyramid Principle[2] by Barbara Minto.
[1]: https://www.amazon.com/Writing-10th-Anniversary-Memoir-Craft...
[2]: https://www.amazon.com/Pyramid-Principle-Logic-Writing-Think...