New Document

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.

Clouds Effect

Now apply Filter>Render>Clouds then Filter>Render>Difference Clouds on the background layer.

Plastic Wrap

Now Filter>Artistic>Plastic Wrap and use these settings:

Now apply Filter>Stylize>Glowing Edges and use these settings as well:

Duplicate layer

Duplicate the layer and set the new duplicated blending mode to Color Burn:

Lens flare

Apply a Filter>Render>Lens flare right in the middle of the bottom layer. Use these settings or modify them to your liking:

Set Color

With the bottom layer still selected press CNTRL+U and use these color settings:

Your done, heres my fire ball: