Begin in the authoring file
Use real heading styles, list tools, table structures, link text, document language, and built-in form controls. These choices carry information that font size, indentation, and color alone do not. Fixing the source also gives later revisions a better chance of remaining accessible.
Give non-text content an appropriate treatment
Write alternatives that serve the image's purpose in context. Mark decorative images so assistive technology can ignore them. Complex charts may need a short alternative plus nearby data or explanation. Do not repeat a caption word for word when it already provides the same information.
Make relationships available without layout
Headings should form a useful outline. Lists should be encoded as lists. Simple tables need identified headers; complex tables need associations a reader can follow. Instructions should not depend only on color or page position. Keep reading order sensible when content uses columns, sidebars, or footnotes.
Test the exported artifact
Conversion can lose language, tags, order, links, form properties, and table relationships. Run file-level checks on the final PDF or DOCX, then inspect headings, images, tables, links, forms, keyboard behavior, zoom, and assistive technology output. Record checks that still need a person instead of treating them as passed.
Publish with ownership
Name the accessible source, publishing owner, review date, and process for corrections. If a document changes often, add accessibility to its editorial workflow. A one-time repair will not protect the next export.