This 2020 presentation from Bronwen Maxson and Mandi Garcia (University of Oregon) shows ways to make online library research guides more inviting and accessible through video with captions, graphics with accessibility features that go beyond the alt text field in image descriptions, an intuitive navigational layout, and adding a personal message.
A recording and PDF of the slides are available at https://scholarsbank.uoregon.edu/xmlui/handle/1794/25340