For those of our visitors that have issues with seeing the pictures/images on our site (or if technical issues arise and the pictures can't be loaded), we're making sure that every picture has a meaningful alt text as a non-visual description of its content. For icons or other embellishments, though, we will provide an alternative if necessary, and hide it for our visitors using screen readers if it is only decorative.
We want to make sure everything on our site is easy to see and read. For text, we've tried to use large, rem-sized (zoomable), readable type. For images, they ought to be large enough to see, and every element should have a high colour contrast with its background.
Not everybody uses a mouse to surf the web, you know. For our visitors using their keyboards or other such input devices, with or without a screen reader, we want to ensure that our site is easily navigable. Where applicable, we've tested our site to ensure that we can Tab through the site, that focused elements have distinct, obvious styles, and that everything that should be tabbed to can be (buttons and links especially).
The HTML Living Standard includes a lot of semantic, meaningful element types. We make use of them wherever possilble. Some of the pieces of semantic markup we use inlude strong and em tags, dialog, nav, main, and section elements. We also seek to make use of ARIA attributes wherever possible, so our friends that use screen readers can make the most sense of our site's content.