When Creating an Email Template, you can simply copy an existing template by selecting the template and clicking the Copy as new button. All the setup fields will be pre-filled and you only need to review and make any necessary edits. 

To copy an email template:
  1. On Email tab, click Templates
  2. Select desired existing template, click Copy as new
User-added image
  1. Enter new template name, click Save
User-added image
  1. Modify new template details