A striking pattern in its own right, this Energy Warp effect can also be used to produce great brushes; just make sure you use highly contrasting colours for maximum impact.
Open a new image with a transparent background. Press D on your keyboard.
Go to Filter > Render > Clouds, then Filter > Render Difference Clouds.
Press Ctrl and hold down whilst you press F. Do this 3 times.
Go to Filter > Pixelate > Color Halftone and change your settings to these:
Go to Filter > Distort > Polar Coordinates and make sure Rectangular to Polar selected. You should have something like this:
Next, go to Filter > Blur > Radial Blur with the following settings:
Press Ctrl and F once, then go to Image > Adjustments > Hue/Saturation and colourise your image. Alternatively, see my colourising tutorial.
Go to Layer > Duplicate Layer then in your Layer Palette (bottom right of your screen), change the blending of your new layer to Overlay:
Go to Layer > Flatten Image, then save. Here’s mine: