Some people are able to sit down and compose a post seemingly from thin air. They go with the flow of their writing and with very little editing things may just turn out right. Others study a subject, find links, resources and compose their hubs and articles to a detailed plan.
Which method do I use?
For a personal hub or article I often just sit down and write. These articles would be say my life with my dogs or a personal experience from being blind.
Posts such as book reviews do require some planning and resource gathering. The most important information gathering task of course with a book review is to READ the book. I have seen some reviews where it seems the reviewer has read other reviews and rehashed other peoples work. Not a good experience for a reader. Other areas which I have researched have been articles where I have needed to report on medical matters, signs and symptoms of a problem etc.
My advice is to take account of your articles purpose. To inform on a serious matter? Then research and information is the key. Report on personal experience or to entertain then you may be able to create a hub or article with very little research, flying by the seat of your pants.
Which ever method you choose find what works best for you and stick to it. If you are enjoying how you write then your readers will enjoy reading your work.