Now we’ll create the shadow. In order to do it, wel’ll enlarge the canvas, in a few minutes you’ll see why. Go to Image > Canvas Size. Click the middle bottom box, Make sure Relative is Unchecked and set Height to 1600 pixels and hit OK. Select the "Background" layer, drag a Vertical guide [hit Command+R to bring up the rulers if you don't see them] and snap to the center of the document. Then select "Awesome" and "Shadow"layers and horizontally center them to the the guide.