1. Open a new document (any size you like) and fill it with a black background.
2. Go to Filter -> Noise -> Add Noise (Set noise to 25, Gaussian, Monochromatic).
3. Go to Images -> Adjustment -> Threshold (Set Threshold to 163).
4. Create a New Layer and fill it with a black background.
5. Go to Filter -> Different Clouds.
6. Press <Control + F> twice to apply Different Clouds two more times.
7. Go to Images -> Adjustment -> Auto Levels.
8. Go to Images -> Adjustment -> Hue/Saturation.
9. Click 'Colorize' and Set Hue 0, Saturation 50, Lightness 0.
10. Go to your Layer Mode and set it to 'Screen'.
11. Create a New Layer and fill it with a black background and Repeat Step 5-8.
12. Click 'Colorize' and Set Hue 268, Saturation 30, Lightness -20.
13. Select 'Screen' on your Layer Mode
14. Create a New Layer and fill it with a black background and Repeat Step 5-8.
15. Click 'Colorize' and Set Hue 38, Saturation 81, Lightness -32.
16. Go to your Layer Mode and set it to 'Screen'.
17. Lower the Layer 3's Fill to 45%.
It's done. You can make a nice desktop background image with this method. Experiment with Lens Flairs, Brightness, & etc..
Good luck.













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