- Then hit D on your keyboard to set default colors.

- Create a new layer.

- Now go to filter>render>clouds. Then filter>render>difference clouds. Now hold ctrl and press F about 10 times.

- Now go to image>adjustments>levels and change your settings to match mine.

- Then go to image>adjustments>hue/saturation. Then click on colorize and make your settings match mine.

- Now duplicate the layer and go to image>adjustments>hue/saturation and click on colorize again. Match your settings with mine.

- Now place the red layer on top of the yellow one.

- Now click on the red layer and change it to overlay like in the picture.

- Then hold ctrl and press E once to combine the two layers. Now duplicate that layer.

- Now click on the smudge tool with the 100 feathered brush.

- Smudge from the fire hotspots to make the flame look bigger and more like a fire. You can smudge it however you wish to fit your needs. You can smudge it into a spiral, be creative.
example:
before       after

- Now change the layer that you smudged to lighten.

- And that's the end, here is what mine looks like.