There are two ways to copy Active and Ended eBay listings to Drafts:
Use the Bulk Actions menu.
Edit or duplicate the item.
Option 1 - Copy to Drafts with the Bulk Actions menu
Select listings (in Active or Ended) with the checkboxes on the left of each listing.
Pro tip: use filters to home in on certain items.
Use the Bulk Actions menu and select Copy to Drafts:
Create a Draft from an individual listing
In the Actions column, click the Edit button or the Duplicate button:
Make any changes you'd like for your draft,
then use the Save As Draft button: