1. make a new Image (STRG+N) with the size 800x600 or 1024 x 768 or 1280 x 1024 (background colour= white front colour = black)

2. Filter -> Render -> Clouds (default options)

3. Filter -> Stylize -> Glowing Edges (default options)

4. make a new layer with black background

5. Filter -> Texture -> Stained Glass (default options)

6. the second layer(4.) blending options -> general blending -> Opacity to 45%

Now u have something like this:

Now you can do what ever you want ^^