All of this is basically just empathy. "If I were in $position, how would I handle reading this". Answer that question for every value of $position your readers could represent and you won't be far off.
If you write a document and only consider how you read it, it's fundamentally a document only designed to be read by you.
If you write a document and only consider how you read it, it's fundamentally a document only designed to be read by you.