Welcome to my full sig tut. In this tut I'm going to teach you how to make a sig like this:
Step 1
Make a new document. Size 300x100px is what I used but feel free to do what you want to do.
Step 2
Open up the render in the document and let the render fill up the whole canvas.
Step 3
Go to Filter > Blur > Motion blur > 45. 120
Step 4
Put your render in your sig and make in the size that you want I've got this:
Step 5:
Duplicate the render layer
Step 6:
On your duplicated layer go to Filter > Blur > Radial blur > 100, zoom, best
Step 7
Duplicate the radial blurred layer and place it over your sig fill the whole canvas.
Step 8
Merge all radial blurred layers together and set the blending mode to 'overlay'. Now I got this:
Step 9
Add a custom shape to your signature and set it to overlay now you can add a drop shadow or what ever you want.
Step 10
Add a pattern to it and set it to soft light and 28% fill.
Step 11
Add your text
Step 12
Add a border 1px black inside
Final result
I hope you enjoyed this tut!
More Tutorials: 
