This is my fav, and first tut. i have ever done.

Flaming grunge is very simple if you have a set of grunge brushes it always gives you a different look!


Here are some of the looks you could end up with




Every one of those was just changed colors and layer styles.
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Ok first take a 500x500 image and grunge just keep going until you like it
ok
now, Copy it Select it all Ctrl+c you know the process
now go to your sigs background and paste 3 Times...
Select the layer and Ctrl + u on every Layer "Click Colorize" And just pick random colors, no real process. Green Red Blue Try it look at the effects...
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now once you have done this
Overlay, Screen, Lighten, Darken, Color burn, Linear burn play with mostly those layer styles, try others but youll figure out which ones to stay away from
For your first time you can try to use this ""Overlay, Color burn, Normal"".
now move the images around remember their 500x500's find a part you like and then youll get a effect. add on your stock, blend do the rest of your work and use the background
if you decide to use this post your backgrounds/sigs made from this.
Thanks
- Grogerian

did this tut. a while ago but if im not mistaken i used Lightning brush set, and Total Deviance.

Anyways this tutorial here was first posted on another site. i reworded it,
if you dont understand something, i can try to clarify it for you.