“One technique I’ve used for years is to ‘design in text’... not necessarily describing everything in textual form [...] essentially what is the message that needs to be communicated if I was only able to provide the user with unstyled HTML?”
I recommend a process that takes us incrementally and cumulatively from the smallest and simplest aspect of our design to the largest and most complex.
You’ll be applying styles incrementally, such that their cumulative effect will be to visualize the design(s) you’ve sketched. ! You’ll do this by sculpting the content using simple CSS. ! Most of these styles will be used (or in some cases, overridden) in the larger screen layouts.
When sculpting text: ! Do it methodically. Only add CSS where needed. Avoid complex CSS (for now). Avoid complex layout. Keep checking on real devices.