There are basically two ways to write a blog post. One is to consider your topic and what you want to say for whatever period of time in your head and then just sit down and write the post. The extreme of this method is treating the blog like a journal and literally write off the top of your head. The other is to write the erstwhile post first, before posting it using the blog format. So you might write your essay using Word or some other program, then cut and paste it into Blogger or Wordpress or whatever.
Usually, I live blog. I think about what I want to say in my head, then try to translate those ideas into words, trying to be clear, considering length etc. Sometimes a post is an expansion of a Facebook post or a comment on someone else's blog but still it is not a "second draft" of an essay. I suppose my writing would be better if I wrote drafts but it takes some of the passion out of the writing, some of the immediacy out of it. Live blogging is not always easy; posts sometimes take a l-o-n-g time to compose. Sometimes ideas just will not cooperate. The essay goes in circles. The writing just stinks. Something important ends up being unsaid.
Sometimes I do write drafts. Even with the Blogger iPhone app, it is easier to write on the note function of the phone. When this happens, it is a draft and it gets revised a bit before transfer to Blogger. Very rarely I feel that a post requires extra care; hot topic, need to fact check, like that--in that situation i might write a draft. Hazards of live blogging? Perhaps a post that isn't perfect. For example, while I was pretty happy with Saturday's post on crime, I didn't take time to get into the role of education, I didn't talk about the issue of keeping hope alive, and I wasn't completely happy with the phrase "the rest of the city needs to be protected". On the other hand I like the post for its impact as you read it.
There's a saying: the perfect is the enemy of the good. If I fret over how far from perfect my blog posts sometimes are, nothing would ever be published. That rather misses the point of writing doesn't it. It also is more stressful and much less fun.