Abstract Signature Background

Open up a new document 400x150 with white background, and draw diagonal lines like so: (they don't have to be perfect)

Filter > Stylize > Wind (from the left) and Ctrl+F

Duplicate the layer, Filter > Distort > Twirl (angle 248) and Ctrl+F then Filter > Stylize > Find Edges and set the layer blending mode to darken.

Ctrl+U, check colorize, and pick your favorite color (I chose +30 with lightness +30 as well), then duplicate the layer, flip it horizontal, and set blending mode to darken.

Merge layers, duplicate the layer, flip vertical, and set blending mode to one of the following:

Darken:

Lighten:

Color Burn:

Now (using multiply as the example), merge the layers, duplicate it, Filter > Blur > Gaussian Blur on the top one with radius 2.3, and set the blending mode to lighten.

Final result: