Maintaining a standard for the use of layers in your drawing is easier if you have a drawing template with predefined layers, and styles that reference those layers when objects are created.
For consistency, save your template as an AutoCAD standards file (.dws format). Then, in the template, enter the STANDARDS command and in the Configure Settings dialog box, link the standards file to the template. If you want to enforce the standards, you can click the Settings button and activate notifications of standards violations, or override such violations. See AutoCAD Help for more information about the use of standards files.
For more information about layers, see Layers.