Do you have suggestions for ways authors can improve communications with their publishers?
Hmmm, do you mean how can you communicate with them? Or how do you get them to communicate with you?
Some publishers/editors are lousy communicators—they rarely return phone calls or e-mails, and when they do, they don't give satisfactory answers. This stinks. It shouldn't happen. Communicating with the author is part of their job and they should do so in a professional and timely manner. If your publisher/editor is a bad communicator, there is probably nothing you can do about it. Sorry.
Some authors have unrealistic expectations of the time a publisher/editor can spend with them. I have authors who call once or twice a week and want to spend an hour talking about the problems they're having with their current work in progress. This is very inappropriate and, I confess, I often duck their calls. I have others who call regularly to see if the edit is done, how many pages have been typeset, if the files are at the press yet... This is inappropriate too.
But assuming you are a professional and realistic author and you're working with a professional and responsible publisher/editor, just ask them what their expectations are. Do they prefer phone calls or e-mails? What is their average response time? What types of communications do they want from you? (Example, I want to know when my authors are doing marketing/promo activities so I can help support those.) If both parties are reasonable, it shouldn't be too hard to work something out.