Attached Link: http://www.renderosity.com/tut.ez?Form.ViewPages=920

Glad you won't eat me! =) I would be too afraid of not tasting good! =) This is a link to my tutorial. Instead of creating a new scene with a fireball, just start at the postwork and use your scene instead. Or (as I did), cut and paste your flame (and only your flame if you can help it) onto a new layer, and do it from there. This way you avoid smudging your background. Good luck! Really I don't taste good! At least not without salt! =)