err... there are actuall tons and tons of ways... if you want it on text there are tons of tutorials out there... but what i use is i first brush streaks of orange, red and yellow and then use the smudge tool...
take a shape or text and rotate it sideways, then use the filter wind on it then you plastic wrap and neon glow, tweak the colors or hue whatever until you got a nice fire
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whew actually you did good for fire just needs some more color into it... you should make multiple layers of fire and make some transparent and others not