Easy tutorial: Photo montage wallpaper

Step 1:

Start by creating a new document with the same dimensions as your desktop, and insert the image that you want to work with in its own layer.
If the image is to big resize it to any appropriate size that suites you’re desktop.


Now we are going to split the image into smaller parts.
Go to View > Rulers, you should now have a ruler above the document and one ruler to the left of the document.
To add a new guide simply click and drag from one of the rulers to the location where you want a guide.

Step 2:

When you have all the guides in place it's time to create a layer for every piece of the picture.
Create a selection inside the first square with Rectangle Marquee Tool, hit ctrl + j to create a new layer from the selection.
Now go back to the image layer and repeat this step for every square you have.

Step 3:

Now you can delete the original image layer by dragging it to the garbage can.
Select the top layer and double click it to open the Layer Style dialog.
We are going to use the Drop shadow and Stroke options for this effect and you can see the settings in the images bellow.
To apply this settings to all layers right click the layer you just styled and select Copy Layer Style, right click every other layer containing a square of the image and select Paste Layer Style.

Step 4:

Now it's time to rotate every layer in a unique way, to do this hit ctrl + t and move the mouse to one of the four corners, the mouse should look like the mouse in the image to the left when you are at the right location.
When you are in the right location simply click and drag until you are happy with the rotation.
Repeat this on every layer containing a part of the image.

Step 5:

To make this picture look better change the layer order by dragging the layers around in the Layers window.
As far as this tutorial is concerned we are finished now, but I will give you some tips how you can improve it further.
You can change the light on the individual images by going to Image > Adjustments > Levels, by doing this it will look more like the images are taken separately.

The result