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 WHITE.
2) Apply Filter>Render>Clouds. The Filter>Sketch>Halftone Pattern and use these settings:

Apply these Hue settings (CNTRL+U):

3) Duplicate the layer and set the blending mode to color dodge:
Apply these final Hue settings to the duplicated layer:

There ya go, done! Here is my effect:
 |