Personally, I avoid deus ex machina like the plague - if you have to use one, it means you failed to set up the universe and the plot properly. It's like a whodunnit where there's no actual way for the reader to identify the perpetrator before the climactic reveal: there's no sense of closure for the reader.
Charles StrossI have no policy, for or against: only a personal style. Which is to say, I use them when I think it's appropriate to; for example, an internal monologue by a locquacious and verbose narrator is more likely to be larded with adverbs than an exchange of instant messages between cops at a crime scene.
Charles StrossBack before the internet we had a name for people who bought a single copy of our books and lent them to all their friends without charging: we called them "librarians".
Charles StrossI wanted an agent who would actually sell stuff. After two British agents failed comprehensively, I was reading Locus (the SF field's trade journal) and noticed a press release about an experienced editor leaving her job to join an agent in setting up a new agency. And I went "aha!" - because what you need is an agent who knows the industry but who doesn't have a huge list of famous clients whose needs will inevitably be put ahead of you. So I emailed her, and ... well, 11 years later I am the client listed at the top of her masthead!
Charles StrossI don't keep anything on paper (except within an actual novel in progress, at which point I need a file to keep track of plot threads, characters, and so on).
Charles Stross