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) Make a new Layer. Now grab the Custom shape tool. Make sure you select a nice shape to use. Something with lots of waves in it. For example I used the Sun shape:
6) Duplicate the layer again and now we want to Edit>Transform>Flip Horizontal. After flipping the duplicated layer we once again want to ermerge the layers together again. Once emerged apply these Blending Options to the layer (Right click layer and select blending options):