Although this article from Automattic about inclusive design is not specifically about designing course materials, it is incredibly relevant to those of us who are trying to create a more inclusive classroom environment.  I highly recommend that you take the time to read it.

Some important points from this article include:

Use accessibility practices to avoid barriers.
There’s no inclusion without accessibility. Accessible designs will present differently depending on the medium you’re working in; consider physical, visual, auditory, financial, and other factors as well as an individual’s temporary or permanent limitations to accessing each. Is your video accessible to someone with hearing impairment? Is your website accessible to someone with a low internet bandwidth? Is your copy readable by individuals with different education levels, for whom the text is in a second language, or who are new to the subject matter? The more contexts you consider, the more accessible and inclusive your designs will be.

 

  • Create for clarity and consistency.Consistency begets usability. Inconsistency creates obstacles. Consider good wayfinding: be clear and consistent with icons, text, colors, and typography to allow the audience to easily follow the system through a changing space. The consistent use of an icon with the word helps orient children, those who don’t speak the interface language, and those who are distracted.

  • Choose copy and imagery with care.Welcome a broad range of people in your imagery and words, because representation matters. While you’re aiming for consistency, avoid sameness. Make sure illustrations, photos, and videos don’t favor one race, gender, age, weight, or other characteristic that will exclude many others.