After I had made some smoke wisps coming off the fish's tail the same way I'd made the flicks of fire, I wanted to add some "smoky stars". I Googled a four point star and opened this in Photoshop. By selecting the star, I then defined it as a custom brush to use on my fish.
Back in the firefish file, I was able to select the newly defined brush from the brushes menu. I made this large and then used it stamp some stars around the smoke wisps.
I wanted some stars to be a bit tilted, so I went and changed the angle of the brush to 45 degrees. I made some more stamps with the tilted brush.
The tutorial wanted a picture of the earth to be inserted behind the fish, but I felt my wispy fish would benefit more from a moon. So I found a picture of the moon on Google, saved the file, then added the new picture as a layer by dragging into the fish file.
The full moon picture didn't quite fit, so I added a layer mask and hid parts of it until there was a crescent with a splattering of small stars left around it.
Next, I added a shadow to the fish. Using the pen tool I drew a solid wobbly shape to act as a shadow. Then, I added a motion blur from the filter menu.
I applied the blur twice. The first time for the x axis and the second for the y axis to create a nice, all round blurriness.
After everything was complete, I made all layers visible and merged them together to the final product.
I exported the file as a JPEG and this is how the picture turned out.