Duplicate a Layer?

The fastest way is to press Command-J (PC: Ctrl-J), and boom—an exact duplicate of your layer, right above the layer you were on. If you’re charging by the hour, you can, instead, click on the layer you want to duplicate and drag it onto the Create a New Layer icon at the bottom of the Layers panel (it’s just to the left of the Trash icon). That creates a duplicate, too.