How to Drag and Drop Layers in Photoshop CS6
To copy an entire layer in Photoshop CS6, simply select your desired layer in the Layers panel, grab the Move tool, and drag and drop that layer onto your destination document. Or simply drag the thumbnail of your layer in the Layers panel onto your destination document. Photoshop automatically introduces the dropped layer as a new layer above the active layer in the image.
However, if you want to copy just a portion of the layer, make your desired selection, before you drag and drop with the Move tool. If you want the selected element centered on the destination image, hold down the Shift key while you drag and drop. See the Bypassing the clipboard sidebar for more on dragging and dropping.
You can also drag and drop a file, not just within Photoshop, but from most anywhere — your desktop, your web browser, and other applications. Simply open a Photoshop document and drag and drop from your source onto that document. By doing so, you create a new layer in that document. Be warned, however, that sometimes problems can arise if your color spaces, color modes or file formats don’t match.
To drag and drop your images, be sure to specify that your images float rather than specifying they’re tabbed. To do so, choose Window→Arrange→Float All in Windows.
What if you have multiple elements on one layer and want to select only one to drag and drop? Simply grab the Lasso tool and draw around the object. You don’t have to be super-precise, but don’t include any portion of the other elements on the layer. Then, hold down the Ctrl key (Command key on the Mac) and press the up-arrow key once. The element then is neatly selected.
Not only can you drag and drop the element, but you can also move or edit it without affecting the other pixels on the layer.