Whenever you have 400+ words per article or more, your article becomes a candidate for the ‘whitespace’ recommendation… which is: Make your article easier to read by hitting enter a little more often, use bullet points and numbered lists and best of all… use SUB HEADS.
Sub-Heads are often best done AFTER you’ve written your article because you’ll have better clarity as to what they should be and at what interval to insert them. You may even want to make your sub-heads stand out by making them BOLD. A typical article template might include 3-5 sub-heads and 1 to 2 paragraphs per sub-head.
The idea is to make your information easier to digest and increase the efficiency of the knowledge transfer to the reader. This leads to increased confidence and respect from the reader and thus more referrals, traffic and syndication potential for you and your articles. :-)