if you like the sytle of the images that you have used for that wallaper. i would say either try vectoring it or images
like that you want to use or even try air brushing to get a similar softened effect like the style used to draw
that.
to really start to advice as a wallpaper artis in photoshop or what efect you may do in photo shop one thing i have
learned is that with out the use of the free brushes ones you make yourself of the main one the ones you download then,
it makes it that much harder to advance.
i was stuck in the same loop for a while not using brushes at all and ended getting stuck as i didnt understand how
others made these amazing pieces. but once you learn the art of creating and using brushes, it then opens up a door way
that leads to mutliple possibilities when also used with other filters and blending mode.
Also it is best to mess about every so often with filters and blending modes so that you get a feel for what each filter
can do, this way you will have a better idea in the future about how to make a certain kind of background or effect that
you may be after
last but not least always try and put at least an hour or so in a week, even if you dont have an idea for a wallpaper,
as it keeps you fresh and upto date with the software.
hope that helps