Step 2: With your image selected, hold the ctrl key and shape the image how you would like. This step is optional. You can stretch and skew the image however you want to make it appear more 3D or flat.

Step 3: Select the Polygonal Lasso Tool (L) and make a triangle around the area you want to build the page curl on. We will be deleting this area.

Step 4: Delete the corner with the delete key.

Step 5: On a new layer, use the pen tool (P) to outline the area you want to be folded or curled over. If you've never used the pen tool before, don't press and hold, click the three corners of the triangle to make straight lines.

Step 6: Using the pen tool, add two more anchor points where we'll be curving the fold. If you don't want your fold to have curves, you may skip to step 10.

Step 7: Using the direct selection tool (A key), select the anchor points and drag them slightly inwards or outwards, to shape the curve of the fold.

Step 8: If you end up with a pointed corner, you can fix this with the convert anchor point tool.

Step 9: You may access the convert anchor point tool by right clicking the pen tool, or by pressing and holding alt over the anchor point. This tool allows us to convert the point to a curve, or a curve back to a point. If you want to make a curve a point, just click the point with this tool, and it should go back to a point. If you want to make a point into a curve, click, hold, and drag on the point with this tool. This will create (or remove) the handles for modifying the curvature.

Step 10: Once you are satisfied with the shape of your page peel/fold, fill the path with your foreground color. It doesn't really matter what color you choose, as we can change it later. You can do this in the Paths window, accessible under Windows - Paths, if you don't see it anywhere. Once you have it filled, you can delete the path as we won't be needing it again. If your corner doesn't match up perfectly, use the move tool like we did on step 2 to correct it.

Step 11: Open the Layer Style window by double clicking the layer or by right clicking the layer and going to Blending Options. Select the Drop Shadow option. Play around with the options as much as you would like until you're satisfied with how it looks. Make sure you have the Preview box checked so you can see a preview. Don't worry about the area off the page yet, we'll do something with this later. Focus on the area under the fold.

Step 12: You may add a gradient or a color overlay in the Layer Style. I decided to go with a gradient to try to make it look a little more 3D. Adjust the angle so it looks right. You could also give your paper a colored background if you'd like.

Step 13: Add a drop shadow to the entire page as well (if you want) by following the same instructions as step 11.

Step 14: Right click the corner/page peel layer and rasterize the layer style. Only do this once you're happy with how the drop shadow looks under the corner.

Step 15: Use the Polygonal lasso tool to select the area outside the corner. Make sure you're on the corner layer. There are two drop shadows here - once from the image and one from the corner. I want to get rid of one of them, as it looks darker than the rest of the border shadows with two on top of each other. Delete this area.

Step 16: Use the eraser tool as needed to touch up any remaining drop shadow up there from the corner.

Step 17: All done! You can save the image, or go back through the steps if you're not happy with the result.