I look at every detail of rooms I imagine. If it is not there, I conjure it up. I inhabit the room and experience the noises, smells, and personal details. I work toward emotional verisimilitude in all the details of experience -- the way it happened, even though this is something that in reality has never happened.
I have this theory that what distinguishes decent writing from good writing and good writing from great writing is just how rigorous the writer was in his or her curiosity, just how authentic and sincere they were. In the A-plus books, the writer went to the bottom of the experience and what did he or she find? More bottomlessness. There are no answers, there are only questions.