How to Format Subheads
An effective way to break up long sequences of paragraphs and provide an organizational scheme for your writing is to insert subheads. Here are some considerations:
Subheads should be succinct — just a short phrase with a keyword or two. They should be formatted in a larger point size than the running text, or at least styled in boldface. Consider formatting them in a different type style than the running text; if one is serif (with appendages such as the tail here in the letter t), the other should be sans serif (“without serif”). Many publications and sites match subhead style and font (and color, if applicable) to those of the headline.
The purposes of inserting subheads are to provide an organizational scheme for parts of an article, book, or other piece of content and to offer the reader a break from reading line after line of unbroken prose.
Subheads should be roughly the same distance apart. If two sections are of inordinately different lengths, perhaps one section needs to be expanded or the other should be shorter. Otherwise, look for other points at which to break up the paragraphs instead so that the sections are about the same length.
If you have more than one level of subheads (for sections, subsections, and perhaps even sub-subsections), distinguish them clearly to aid readers in following your organizational scheme. Books and periodicals employ a hierarchical protocol for subheads, such as using all uppercase letters for the top level, headings with headline-style capitalization for the next level, and run-in headings (inserted immediately before the first word of the next paragraph, in boldface or italic type and perhaps with punctuation as well).
If you have a recurring print publication or multiple posts on your website, select a style for each heading level and use it consistently.