Writing does not mean writing with pen and paper here but it means a method to deliver your thoughts, be it via internet, via a book or another way. Skills of writing is not a hard thing all that is needed is a good brain and knowledge of writing.
While writing any document or an article always make sure you know what you want to write, be clear on your thoughts and make up your mind that you are going to deliver what you want to in a very effective way and that is the first and major step that has to be taken towards writing an article. Remember, be ready in your mind and then start writing.
Making up your mind is essential and anyone can do it but it is also necessary that you develop a good and a professional language while you are writing and what you write should be based on the type of people reading it. You cannot write in scientific language for common public can you?
The first paragraph should contain the background and information about what you are writing, the following paragraphs should have the main information and finally the last paragraph should have the conclusion, but it is not that important.
If you are writing for others, make sure that you don't use words like "I". Write as if you are the book talking to the people.