Hey there!
In this easy-to-follow tutorial i will explain how to make this wonderfull effect:

Step 1:
Open a new document á 500x500 pixels or so..
Fill it with black.
Step 2:
Add a couple of lens flares (different ones preferrably)
like so:

Step 3:
Go to Filters > Stylize > Glowing edged and play with the settings untill you get something like this:

Step 4:
Press CTRL+U and colorize it with a color of 210 and a saturation of 50
DON'T FORGET TO TICK THE 'COLORIZE' BUTTON!
You now have this:

Step 5:
Now apply Filter > Distort > Wave.
Don't mess with the settings, just tick the SQUARE radiobutton under 'Type'.
Press 'Randomize' a few times untill you have a result that looks anything near this:

(Don't worry about the darkness, that will be taken care of in Step 6.)
Step 6:
Go to Image > Adjustments > Curves and gently pull the line to the top-left corner.
Mind you to drag the line at the center!
Now this is the result:

Step 7:
Now do Filter > Sketch > Water Paper
and apply the settings:
Fiber Length: 25
Brightness: 60
Contrast: 60
And now this is your result!

Ofcourse, that is only the base of a beautifull picture!
Here's what i got:

A great base for a signature! See?

And ofcourse, if you learned something, why not sign up?