I tried my best with this tut.

1. I always start with size 350x100 pixels and white background.

2. Press D to restart your foreground and background color to black and white

3. Go to Filter > Render > Clouds

4. Then go to Filter > Render > Different Clouds

5. Go to brushes and pick brushes number 39 then brush it a bit not too much

6. Go to Filter > Distort > Ocean Ripple, then set 15 in Ripple Size.

7. Go to Image > Adjustments > Hue/Saturation and click on colorize and choose any color what you want (in Hue) then use saturation and change it in 46. Go change Lightness in -18

8. Then go to Sharpen > Sharpen Edges 2 times.

9. Your image should look like this...(your may be different in color)


10. Your finished but you can add text/render if you want

Your done with signature background, it can be in any size. Hope ya like it.