Use the built in accessibility checkers found in Microsoft software and other products
Make source documents accessible. Any documents or forms will likely be created in a program similar to Microsoft Word and should be made accessible at this stage before converting the document into a PDF.
Fixing PDFs should be a second choice. Scans are not accessible and Acrobat Pro can prove difficult in creating accessible PDFs. Mathematical and scientific notation can not currently be made accessible in PDF. Check finished PDFs for accessibility. Always consider providing an HTML version of a document along with the PDF or in place of the PDF.
However, please note that using Adobe Acrobat Pro may be the best way to create accessible fillable forms.
Use Heading Styles
Use simple language and active voice
Use font sizes no smaller than 12 points
Use clear fonts such as Verdana, Helvectica, Arial
Do not use color as the only way to make information known
Watermarks can impact readability and create low contrast
Provide a table of contents for long documents
Use accessible templates whenever possible
Use of periods between the letters of an acronym may help screen readers say each letter instead of reading one word
Provide text transcript for non-live audio and for video without sound
Provide synchronized captions for all video, animations and webinars
To leave space at the bottom of a page do not use the Enter button or space bar to advance to the next page. Use a page break feature to advance to the next page otherwise you might give the impression that the document has ended
Use alternate text for logos, images, and charts
Tables require alt text and defined row headers (In Word select table properties>alt text AND >row>repeat as header row at top of each page).
Use alternate text for web links and email addresses. Clearly identify the target of the link. Instead of "http://www.kenyon.edu/about-kenyon/" the link could read "About Kenyon." The screen reader alerts the user when they encounter a link. Web-Aim Links and Hyperlinks
Test the created document or media file with assistive technology