Well, after a few questions from people on this and other forums on how I paint fire, I have finally created a step by step article.
So without further ado, grab your fire safety blankets and get to the CD player because "I am the god of hell fire and I bring you.....FIRE!"
Anyway, I always (
ALWAYS) paint over a black undercoat (while this may not be the best method I find it works for me).
So begin by undercoating the entire model with chaod black (or equivalent) paint.
Stage 1Next step is to paint the entire area of flames with scab red paint.
Stage 2Follwoing on from this, give the entire area a light wet brushing (like drybrushing only the paint is still fairly wet, run the brush flat along the surface so the paint catches on the raised areas.) with blood red.
Stage 3Next is a drybrushing of orange over about the top 7/8ths of the flames. I don't actually own an orange paint (I dont really like my old blood angels orange as it is too translucent) so I just mixed blood red with sunburst yellow at about 50/50.
Stage 4After that, mix some more yellow into your orange mix to make it about 30/70 red to yellow(or mix a little yellow into your orange paint if you didnt mix your orange) and again dry brush this over about the top 6/8ths of the flame area.

Note that at this point I decided to paint the metal grating around the torch as the messiest stages have passed, be careful when doing this as any mistakes will need covering up with your mixed colours.
Stage 5After the metal was painted I gave the top 5/8ths or so of the flame a drybrushing with sunburst yellow. The yellow will still be fairly translucent when applied so it will take two or three layers of drybrushing to get right, this gives the perfect opportunity to blend the flame up a little by drybrushing each progressive layer of yellow a little higher than the first.
Don't worry if any of the yellow gets on the metal as this will add to the effect.
after first layer of drybrushing yellow
and after the second layer of drybrushing yellow
Stage 6Finally, mix sunburst yellow (or whichever yellow you decided to use) with skull white about 70/30 yellow to white and highlight the top 3/8ths or so of the flames and thats you done!

You'll notice in my examples that I got a little bit of yellow on the metal, I think this looks good as it looks like the glow of the flames on the metal and all adds to the effect!
Well, now your done you can sit back and relax to some electric 6 and be safe in the knowledge that the heretics will burn by your hand!
(Interesting point of note, when I sat down to paint the flames on the example model I was listening to the song "Learn how to start a fire" by Further Seems Forever from the album of the same name! This was also completely by accident!)
Again, I don't suppose the images will work in this post (Gructh, hopefully you could sort this?

Also if you have any program that could maybe lighten the pics a little would be great as I'm pretty crap at this stuff!)
Images can be seen here:
http://groups.msn.com/CMDantesGalleries/paintingfire.msnw?Page=LastWell, let me know what you think!
Cheers,
Dante