Remember to save your layouts if you wish to use them at a later point. Using the Save command you can save a layout under it's existing name. Using the Save As command, you can specify a new file name and a location in which to store the file.
By giving the layout a different name when you save it, you create a copy of the existing layout while keeping the original intact.
To save a new layout:
To save a layout under a new name
To save a layout that's been saved before: