Good morning! What Baseline said is really true. Gotta get
acquainted lots first with the program so it'll be much easier to
grasp. Anyway, before beginning to try duplicating the signature,
there are some preparations to do. You'll have to download brushes
+ add them into Photoshop. That, find out how yourself. 
Some brushes to try out.
Deviantart.com - Browse Resources - Photoshop Brushes.
Look for the abstract and grungy types.
Or just browse through the tutorial first. 
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So then... we'll start off with the background okay?
Can you see, more or less the resemblance? Its what we are trying
to do.
1. Create a new canvas with the dimensions of Width: 400 pixels x
Height: 100 pixels and "Background Contents" being white.
2. Create a new layer by clicking on the icon shown below. Yours
will turn out the same.
3. Choose a foreground color for yourself. Mine for reference sake
is #FF6666.
4. Select the Brush icon. Choose again, the brushes you want to
use. Then, start dabbling in it. Just "paste" the brushes on the
canvas, like a sponge painting.
5. Create another layer, and repeat the same thing.
6. Keep on doing it, until you are somewhat satisfied.
7. Go to the menu - Layer - Flatten Image.
Next is Image - Adjustments - Levels - Drag the right most arrow
(white color) to the opposite direction as much as you wish.
Okay, done so far.
The designs on the canvas, it all depends on the brushes
you chose. Mine is some swirls and roughness. That sig, is
some other type.
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Now the text.
1. Create a new canvas with the dimensions of Width: 400 pixels x
Height: 100 pixels and "Background Contents" being white.
2. Make your foreground color black and choose your font now.
3. Apply your font.
4. Add a "Layer style" by clicking the icon shown below and then
choose "Stroke".
5. Adjust your own settings and apply afterwards.
There, see the resemblance again? Once more, The designs on
the canvas, it all depends on the brushes you chose.
So keep on practicing and search out other tutorials as well! Have
fun....
