There is no one process for writing a blog post. Some bloggers like to write their posts in advance, while others prefer to write them as they go. Some people like to have a lot of detail in their posts, while others keep it more streamlined. The most important thing is to find what works for you and stick to it.
Here at Digi-Task we write blogs posts on a variety of topics specifially for other people. Because of this our process for writing blog posts is always changing to fit the needs of our clients.