Accessible Websites are Like Essays - A Memory Aid

Creating accessible pages is like writing an essay, you must have all the necessary organizational structures.

Both Must Have:

1. Main headings
2. Sub-headings
3. Text for all explanations of images and meaningful color usage in your UI. (text must be screen reader only, or screen reader and visually available)
4. Labels positioned to maximize predictability of relationships
5. Page numbers for pdf documents

References:
Content Structure Separation Programmatic