Much of what has been discussed seems more like production design than screenwriting.
For Nancy Meyers "The Holiday" the production designer and his team looked at many photographs of screenwriters offices to give them ideas for the workspace of the Arthur character, who is a renowned, retired screenwriter (played wonderfully by Eli Wallach). Besides many (neatly messy) stacks of books, papers and other clutter on his desk, bookshelves and elsewhere there are awards and photos of collaborators on the shelves and walls.
My suggestion/idea is that, as you pan across the room to your character, showing awards, photos, framed newspaper articles, his books, etc. pertinent to the history of the character, he is heard talking on the phone per IndieTalks idea. The phone conversation should give us a real insight into the character; if he is reclusive he responds in a terrified manner to the book signing (if that's what the call is about), with enthusiasm if he is a narcissist, resigned if he just wants to work but knows how important public appearances are to his career. The organization or lack thereof of his office will also give much information about the character, as will the furnishings, color scheme, wardrobe, H/MU, sound, score and a dozens other interrelated details.
Hopefully a few more real screenwriters will chime in.