Alright. In this short tutorial, I will show you how to create what I simplistically call the “Static Ball” design..
(Corny name, eh?)

Alright.. Start off with a blank 300 x 300 pixel image.
- Color the background black in color. (The paint bucket took can be found by right-clicking on the 'Gradient' tool.)
- Go to Filter > Render > Difference clouds. Do this two times. I have found that the randomly generated clouds appear better on the second one.
Here is how your progress should be coming along, so far..
Alright. Moving on.. Go to Filter > Distort > Pinch, then apply this setting in the pop-up prompt. (All you have to do is slide the bar to the right.).
Now, here is a crucial step. Click on Filter > Pinch. You'll know this instantaniously applies the Pinch filter, now.
(This is because it was the last thing you used. If you had applied a Wave filter, for instance, 'Wave' would be available, instead of  'Pinch'.)
Anyway.. Click Filter > Pinch close to 10-20 times. Afterwards, you'll have something along the lines of this result:
Now, for the final step in the design. Go to Filter > Stylize > Glowing Edges. When the pop-up window appears, use these settings..
Click 'OK' after entering in those settings, and you are left with the finished result. This!
You don't have to stop there, though. You can create many cool modifications to it. One of them is the Filter > Distort > Twirl filter.
Try that one, for an interesting whirl-pool effect!