I was reading an article on this subject and I was prompted to write about it based on my experience in writing my blogs. I think what you post depends on the subject matter and how much thought that you have put on it.
The simplest blog would be a cut and paste job from the internet or from the other blog sites. Now that would make you a copycat and after sometime I guess the readers would be able to spot a rat and maybe your visitors would start dwindling.
I write what is in my head and correct it as I go along and I follow this tip that I had read from a book by Lindsay Camp aptly titled " Can I change your mind? -The craft and art of persuasive writing.
Remember the reader and the result (RRR) is a good point to keep in mind and also to visualize your piece as an advertisement, now if you were to place an advert on the newspaper on what you had composed, does it have the impact to pull the buyer(reader) and be swayed by it. An ad (in our case our blog) that doesn't persuade is like a fish that doesn't swim: dead in the water.
I also believe that " Good persuasive writer's don't tell their readers what to think or feel; they say something that makes their readers feel or think it for themselves."(quoted from the book)
It is also very important in knowing the result that you want from your reader/blog beacause if you don't know what you are trying to achieve in a piece of writing(blog), it's impossible to judge how far you have succeeded.
I would be happy if I had imparted some of my thoughts on writing a blog based on my experience and I would have done justice to this piece by taking away your precious time(in reading this blog).
Another piece of advice that I read on a blog was that don't feel ashamed in asking for a response or a comment from the readers. I am just doing that now.