If you always start writing without an organized outline in your mind before starting, you will end up losing track of ideas and the article will be incoherent. Of course not every one or even I am not qualified enough to write coherent articles. But the best way to learn this is to start with an outline in mind of the thoughts and ideas that you exactly want to communicate through your writing.
How will outline help your writing?
Without an outline it will be tough to concentrate on continuing writing and we tend to scatter the elements of writing here and there. This will make the reader find tough to follow your thoughts. If you thought about making it organized before starting you will also think about how to present certain elements like facts presented normally as a list, illustration as a form of picture to the right etc.
It is important of course to start something if not all when you are unable to start writing. But as you progress it will help increase the quality of articles. Once you have learned about a topic and decided to write something on it, you can make an outline in your mind at any point of time either while walking to home, having dinner etc. When writing, it will save time considerably with respect to editing the article.
Conclusion
Learn to make outlines in mind before starting to write articles. Outlines help reduce editing and reviewing time, improve the quality of article and also make the reader easy to follow it. It will also help you in the long run to progress as a writer.