Since I don't have time to do many sigs this week, I made a quick tutorial, whether it will help users, or people making sigs for others, it should help.
This is not a signature tutorial entirely, just a smudging method I use, google "smudge signature tutorials" and use this WITH that tutorial, and you should make a bad ass signature!
THIS IS QUITE AND ADVANCED TUTORIAL, FOR BASIC USERS, GET TO GRIPS WITH THE "SMUDGE TOOL" BEFORE ATTEMPTING.
ALWAYS DUPLICATE YOUR RENDER/SMUDGE LAYERS BEFORE ANYTHING, SO YOU CAN GO BACK AND START AGAIN.
SETTINGS
These are the smudge settings I tend to use, chalk brush makes a great "smokey effect", but you can play around with different brushes and results;
http://i.imgur.com/Kpnx3.jpg
Start with your render (this one is a little smudged to start with sorry, but I'll come to that.) You want to smudge in small circular motions like this, try focus on colours, and what different colours you want to end up "smudged" together, although it doesn't matter if you're going to colour correct it later;
Should end up with something like this, there's a nice ammount of dark/light colours, which will help later on;
This step, you want to use the same settings, and to some fast smudges in direction of the arrows, try to stay away from the parts I've scribbled out, because you don't want to mess up the texture you already created, you're just blending it into the background more;
Now, from the outside, do some small fast smudges back towards your render, try and only smudge it a little, this is to blend the smudges with the background;
The last part of blending it is the click on the edges, don't drag the smudge tool, just keep a few times, this will "fade" the edges out a bit more;
Now you want to pick some colours out from the inside of your render, and following the same rules above, smudge them a little bit into the cloud of smudges you already made, and blend them in.. this stage is only optional if it already looks okay;
Now following the steps you've learned create as many smudges as you want, normal 1/2 is nice, but this time keep the smudges SMALLER than the one you already made, I chose to smudge one about this big, and i played around with the layer styles, and set it to screen/80% opacity;
Put your render back on top, and erase some parts using a soft brush, this will merge it into the smoke you made, you can also smudge a few parts to help blend it in - trial and error;
There you go, the smudge part of your signature is now done, there will a be a video someday to help show exactly how I do this, because it can be quite tricky, hope you enjoy.
edit; by darwish ( fudge's finishing tut
you make an tutorial for it btw tnx for a cool signature 
