I set up the naming conventions for programs and campaigns first, then train. During the training I constantly emphasize the importance of naming convention because it's easier to associate files or find them when the naming convention is consistent. I do monitor everything and I haven't had to send a friendly reminder.
Also a big help to me is only use templates that are associated with your department. For instance for Events, there's always an "Event" on the naming convention so they're not using the Marketing templates or Editorial or sponsorship templates. All images, landing pages and other files in Design Studio have their own department folder, and all departments should drop or access files from their own folders.
Any templates in design studio that I don't want anyone messing around with, I store in a folder called "Do not touch".