The way I do it is this: I create a "templates" folder, and inside it, subfolders for each template. In each subfolder, I put the template file itself, the "rmg.txt" file, and any other relevant information (like a diagram, for example). When I want to play with a specific template, I simply copy the template file from the appropriate subfolder into the "data" folder.
More advanced users just use the HD mod :D :)
