Next, we will add another texture to our scene in order to bind the image together and give a bit more grunge-look to it. Import the Stain Texture image to our canvas (File > Place), then press Shift+Ctrl+] to bring the layer to the very top of all the layers. Set the Blending Mode to Soft Light and lower the Opacity to 66%. Again, copy the layer and place the texture to the bottom part of the scene. Erase the part of it everywhere you don't like it with the layer mask.
Lastly, Go to > Layer > Flatten Image. For the last adjustment, add Curve from adjustment layers and set the setting as shown below. Then crop the image and sharpen your merged piece using Filter > Sharpen > Unsharp Mask. We are done!