I'm a wordy writer. In fact, often I start a piece and easily find myself with 2 (printed) pages of written text in ten minutes. I tend to over describe, overwrite, and try to completely cover a topic.
Then I edit the piece and often remove half the words. Or, what I find happening more and more as I practice, is I break the piece into a few posts.
The key to writing a good post is to focus. Focus on a specific topic and write about just that item. Don't get distracted by ancillary details. If you think your readers need to know more about a related item, that's a separate post.
What I recommend is that you write a sentence that describes what you are teaching. Keep that at the top, and as you write, refer back to this sentence. Your details and discussion should support this topic. If they don't, start a new post with a quick sketch of the related item, and then go back to writing about items that support your topics.
A few examples.
If you are writing about scheduling a job in SQL Server Agent, don't get caught up in the job details, or the security for a job (proxies) or the categories of the job. Those are separate posts. Just show me how to detail with an Agent schedule.
If you're writing about how to wire an electrical outlet, don't give me details about finding the fuse box, or which gauge wire to use, or the benefits of two v three prong outlets. Those are separate posts.
If you're want to talk about cooking shrimp scampi, don't get caught up in how to make the best pasta, or choose shrimp and devein it, or how to chop garlic. Those are separate posts.
Keep your focus. You'll find blogging easier, quicker, and also you will build better communication skills that teach you to focus tightly on the concept you are explaining.