I recently posted a blog on the new Penkhull Press website about maps and their value when writing your novels.
I have read many stories in which the protagonist moves across vast landscapes, through difficult terrains, in unrealistic times, with the minimum of effort. Is it really possible for someone, for example, to track dozens of miles through unfamiliar, dense jungle, lumbered with a backpack, in a few short hours, even at night (unless s/he is a superman/woman, of course)? This contraction of activity/time is a common fault in some fantasy and SF adventures I’ve read.
The essay is meant as general guidelines (rather than rules or a code). You can read the whole piece here.