I take it you used apophysis for this?
Its a good base for doing something further with in photoshop or gimp! Most of the people who make nice fractals in apophysis who are not experts at fractals use a lot of post processing to really give their images the edge. Also don't be afraid to use multiple flames compiled together in photoshop/gimp to make those more basic flames more interesting.
I cant say that any of my fractal art is any good but feel free to take a look! ->
http://afeuillade.deviantart.com/gallery/#FractalsYou can also check the apophysis group gallery ->
http://apophysis.deviantart.com/gallery/