I made a wallpaper for my forum since this is so easy I decided to make a tutorial for it.
1. Make a new document and fill it black.
2. Go to Filter>Render>Clouds

3. Go to Filter>Render>Difference Clouds
4.CTRL+I to Invert
5.CRT+L to pop up the levels.
6.Change the setting to this:
7.CTRL+U to colorize (I used blue)check the colorize box above preview:
8.This is my result:
ONLY POST IF YOU HAVE A QUESTION, ANSWER, OR SUGGESTIONS IN ADDITION TO THE TUTORIAL.
You may also post your results from this tutorial.