Instead of cutting a gaping hole through an image, you can combine two images by using the Paste Special submenu (Edit→Paste Special). The handy items in this submenu let you tell Photoshop exactly where to put the copied image:
Paste in Place. Use this command to paste an image in the exact same position it lived within the document you copied it from. For example, if the image you copied was flush left in the original document, it’ll be flush left when you paste it into the new document. The keyboard shortcut for this command is Shift-⌘-V (Shift+Ctrl+V).
Paste Into. Use this command to paste an image inside a selection you’ve made (in other words, inside the marching ants). Photoshop puts the pasted image on its own layer and creates a layer mask for you, as Figure 8-2 illustrates. You see the pasted image only in the selected area; the layer mask hides the rest. Keyboard shortcut: Shift-Option-⌘-V (Shift+Alt+Ctrl+V).
Paste Outside. This option makes Photoshop paste the image outside your selection. You get an automatic layer mask, although this time the area inside the selection is hidden; the pasted image shows only on the outside. This command is useful for swapping an image frame or border. (Apparently Adobe is running short on keyboard shortcuts because this command doesn’t have one.)
Figure 8-2. The Paste Into command tells Photoshop to create a layer ...