The next lesson I'll show you how to process the colors, to use program's filters, using the layers and create the effect of illuminated objects.

Create firstly a new file of standard wallpapers' size: File – New (ctrl+n).

computer free desktop wallpaper

Now we have to paint the layer, applying the Gradient Tool (the stretching should be done vertically, from the top to the bottom).

computer free desktop wallpaper

Then
create a new layer: Layer – New – Layer and choose the Pen Tool with Fill Path command to draw arbitrary several ornaments:

computer free desktop wallpaper

Apply the next shown filter to this layer: Filter – Distort – Polar Coordinates.

computer free desktop wallpaper

That is what we get:

computer free desktop wallpaper