1. open a new image. As always, I make mine 400x400 pixels
2. Make your foreground color black and your background color white. Go to Filter->Render->Clouds. You're image should look something like this:
3. Now you're going to want to go to Filter->Distort->Pinch. Use a value of 100%.
Do this around 4-7 times. You choose. This is what I got after doing it 6 times:
4. Now, time for the fun part. Go to Filter->Render->Lighting Effects. Here are the options you should try to chose:
The image might look a little something like this:
5. Next, you want to go to Image->Adjust->Hue/Saturation. Depending on what color you want to use, you can just fool around with the settings. I want a really neat blue, so this is what I did:
And this is what I got:
Pretty easy, eh?
You can fool around with a bunch of other things to get different effects. Here's one of the graphics I did with this "Burst Background". Right here