This is one of those Photoshop tips that you’ll either use all the time or never.
Press Command-Option-Shift-E (PC: Ctrl-Alt-Shift-E) to Stamp Visible layers, which creates a new layer on top of all the visible layers below. This is really useful when you want to apply a filter to the compiled image but want to keep all of your existing layers intact. The only downside is that it can increase the file size dramatically.
Bridge CS4 lets you quickly get a full-screen preview of any image. Select the image and press the Spacebar or select the Full Screen Preview from the View menu. This opens the selected image in a full-screen preview. Click on the image and it zooms to a 100% preview; Control-click (PC: Right-click) and drag on the image to move around; press the Arrow keys to move between images. Pressing the Spacebar a second time returns Bridge to the previous mode.
If you hold down the Shift key while opening an image in Photoshop from Camera Raw, it will open as a smart object. You can also set this as the default action by clicking on the Workflow Options link under the image (the blue, underlined information that looks like a hyperlink), and checking the Open in Photoshop as a Smart Objects checkbox.
Sometimes, targeting a specific color channel can help create a much better selection, especially if there are distinct color differences you can take advantage of. In this example, the same diagonal move with the Quick Selection tool resulted in a much better selection of the heart when it was applied only to the Red channel in the Channels panel (Window>Channels).
