true representation i think can come only from one thing : personal observation. if you want to learn how to draw anything, the best way isnt to ask someone how to draw it, or look to other artists for their own representations, but to study it for yourself. if you want to learn how to draw fire, go get a zippo and look at it. hold it out, hold it close, cup your hand around it to see how it effects the movement. flick your fingers through it and watch it move. Id say about an hour of real concentrated observation (playing with fire) will give you a much better idea of how to draw it, and you may not even need help after that