To duplicate an item, select and click on the specific item (a work order, tool, material, etc.) and you will be directed to the item's detail view.
Locate and click on the "Duplicate" button (usually in the top right of a section).
You will be redirected to a new page nearly identical to the original detail view, but the name of the item will now have the word "copy" added to the end. When you return to the list view, your duplicated item will appear at the top of the list.