Draw the lines you need for the torn effect starting with the Lasso tool. After that, build a new layer that will serve as the paper edge and apply a Layer mask to conceal the region that will be outside of the selection. By selecting Paint Bucket, add white to the last layer you created. When dragging the Paper edge layer below the Model layer, hold Control-D to deselect it. The paper edge may then be positioned where you want it using the Move tool. Select the Warp tool to alter the edge’s form so that it seems natural. Then, drag the desired texture onto the Paper edge layer to create background depth using the Drop Shadow option.