i think it does look pretty cool. looks really ghosty. my suggestion is:
in the pic.
where the arrows are pointing. you should add your brighter colors toward the edge to the middle. this gives you a depth effect.
other than this are like where the blue and purple are:
make the flames overlap and have some action.
just keep practicing and looking at pictures of others work. find out what you like about them, imulate it and come up w/ your own style. i've been working on them for at least a year, and i'll always be practicing at them and getting better.
good luck!