This will be a short Photoshop tutorial that will explain how you can make an image richer by adding a texture to it.

We start with this image that can be found on the internet:

Then we straighten and flip it in Photoshop using Image > Image Rotation options:

There is a more or less flat backdrop to the guitar. We want to introduce a texture here. You can download textures from the internet, like this crumpled paper texture that I chose:

Insert it into the document as a layer, like so:

Resize it so that it fills the entire area, in this case:

Now comes the magic. Set the blend mode of this layer to overlay. You can experiment with some of the other modes too to get your desired result:

This is the result:

Not quite finished yet. The overlayed texture has fallen on the entire image, including the guitar. Although in this case it is not very conspicuous, I still prefer the smoother, softer original look of the guitar. Also, in other cases it might not do to have the texture sprawl over the entire image, but only lie over a specific area of it. For this we must remove the texture from the unneeded region. This we shall do via a layer mask.

Apply a layer mask to the texture layer by Layer > Layer Mask > Reveal All:

Now choose a suitable brush:

Paint with black over the mask of the texture layer. This will start removing the texture from the regions you paint over. Paint with white to restore the texture in that area. Toy around with the brush size, hardness and opacity; change brushes etc. until you are satisfied with the result:

As you can see, some softness has been restored to the guitar and the surrounding background. Now you may, if you want, merge down the two layers by selecting the top layer and pressing Ctrl+E or choosing Layer > Merge Down and use it as a single layer or save as an image.

This essentially concludes the tutorial on adding a texture. However, I also wanted to increase the extent of this image upwards, filling the expanded region with only the textured background. For this we must first make a layer from the locked background (the original image) by double-clicking it. Then we change the canvas size by Image > Canvas Size:

If we do not make a layer from the background before expanding the canvas, the new area will be white instead of transparent.

Then I duplicate our layer into a new one and shift that up. I flip it vertically and line it up with the top edge of the original layer below:

We need to make the top guitar disappear. We do this using the Clone Stamp tool. Choosing a patch of the textured background beside the top guitar as the source, you can paint over the guitar. Again, fiddle with the size, hardness and opacity of the brush to smoothen out the changed region with its surroundings.