DRAGGING AND DROPPING WHERE YOU WANT

If you drag an image from one document to another, the dragged image appears right at the spot where you let go of the mouse button. You may know that if you hold the Shift key when you drag-and-drop the image, the dragged image will automatically be centered within the receiving image. But you can go one bettermake a selection in the receiving document, then hold the Shift key before you drag. Your image will be centered within the selection, instead of within the entire document. Scary, isn't it? You can also copy-and-paste the selection and Photoshop will center the pasted image in the selection.