Clients always ask me etiquette questions, and they are ALWAYS good questions. Some really depend on the situation and obviously, your own opinion about the specific issue. Sometimes, I have to ask multiple questions in order to figure out what the right answer will be for that specific client. Here is a good comprehensive list of the top 24 etiquette questions by Real Simple to at least guide you through some of the common ones.
(photo by Carlie Statsky)