Christmas themed wallpaper from scratch. A Well explained & Easy to follow Tutorial!
Create a new file (
File>New) that would have
1280x1024 px and
72 dpi.
Now we shall use the
Rectangle Tool (U) to draw the background of the picture to be.

Set the next parameters for the made layer by making a mouse click on this layer on the layers’ palette.
Blending Options>Gradient Overlay
Gradient’s parameters: 

Next we’ll represent the snow hills, applying the
Pen Tool (P) and
Convert Point Tool for the corrections on the made elements.

The layer’s parameters:
Blending Options>Inner Glow
Blending Options>Gradient Overlay
Gradient’s parameters: 

Next choose the
Custom Shape Tool (U) and pick up a fir tree’s figure, having the color
#003274 

Make seven copies of the tree’s silhouette and select the
Free Transform option to change the copies’ sizes, placing them the same way demonstrated below:

Using the
Custom Shape Tool (U), let’s represent a lot of snowflakes, having different sizes:


Continue representing the snow hills, selecting the same
Pen Tool (P) and
Convert Point Tool, having the color
#A7FEF6