Text & colour
In order of priority:
- Text size. Significant granularity between 1x and 2x, less so afterward. Most users will not need more than 4x (depends on defaults).
- Contrast and colour. Should include, at minimum: black-on-white, white-on-black, yellow-on-black, black-on-yellow. Might also include inverted contrast and grayscale and brightness alterations.
- Line spacing. Significant granularity between 1x and 2x, less so afterward
- Text style. Should include, at minimum: Verdana, Comic Sans, Arial/Arial Black, Times New Roman
Layout & navigation
- One-column/simplified layout
- Table of contents
- Link emphasis (underline, bold, larger?)
- Larger inputs (e.g., buttons, form fields, radio buttons, check boxes, etc.)
Other things to consider
- Background images (should this fit under the contrast & colour schemes?)