As shown in the Art Gallery, this is the tutorial for my Fire Sphere effect:

1. Create a new canvas, about 500x 500, white background. Zoom out once(66.67%).
2. Using the Brush tool (size 13, 0 hardness), make some squiggles in the color of your choice (I used #993333) towards the center of the canvas.
3. Using black, make more squiggles in the center. Don't worry if these cover the old lines - you don't want there to be as much color as black.

You should have something like this:


4. Now comes the Filters...
Filter > Brush Strokes > Accented Edges
-- ( Edge Width: 1; Edge Brightness: 35-40; Smoothness: 5 )

Filter > Artistic > Cutout
-- ( Number of Levels: 4; Edge Simplicity: 4; Fidelity: 2 )

Filter > Brush Strokes > Spatter
-- ( Spray Radius: 10; Smoothness: 5 )

5. If you have Photoshop CS, you should have been able to do that all at once by using different Filter layers. You now need to press 'Ok' though, because you won't find the next Filter in the Filter Gallery.

If you don't have the Filter Gallery, it won't matter, just continue with this step.

Filter > Distort > Polar Coordinates
-- Polar to Rectangular

6. Now another Filter...
Filter > Brush Strokes > Angled Strokes
-- ( Direction Balance: 50; Stroke Length: 50; Sharpness: 3 )

Your image should look something like this:


7. Almost done!
Filter > Distort > Polar Coordinates
-- Rectangular to Polar

8. Last step! Using a large brush size ( I used 300 ), Burn the entire image to give it that ember look.
Note that you may have to focus your brush size down to about 20 to remove any lines left my the Polar Coordinates Filter.

Here's my final result: