1. Make a 400x400 document. Now press "D" on your keyboard to reset the foreground and background colors to black and white. Make sure your background is black.
2. Select the Gradient Tool
and make sure you have the Gradient at the top set to white to black. Also select Reflected Gradient button:
Don't make the gradient lines to wide, try and keep them relitively thin. After your done filling in the general area of the canvas:
3. You want to apply Filter>Brush Strokes>Crosshatch and use these settings:
4. Apply these Hue settings by pressing Ctrl+U and using these following settings:
There you go, you just created a cool deviant abstract background.
