Here on this tut i will show you how to create a Rust Metal Background so first things first.

1.-: Star by making a new Document any size (I used a 370x120) and fill it with your paint bucket tool black color, and then select your gradient tool and set it to Diamond Gradient and Mode: Difference

so now Go wild making small & large diamonds until you get something like this:

dont worry if mine doesn't look exactly like yours as it should looka liittle different.

Step 2.-: Now go to :Filter: the istort: nd finaly :Glass:

and used these settings:
Distortion: 5
Smoothness: 3
Texture: Frosted
Scaling: 100
Invert Box: unchecked

Step 3.-: Now go to :Filter: then :Brush Strokes: and finally Ink Outlines and use these settings:

Stroke Lenght: 4
Dark Intensity: 20
Light intensity: 10

Step 4.-: Now for the final step bring up the Hue/Saturation Box By clicking CTRL+U and check the Colorize box and change the color to any color you wish I personally used for this tut HUE: 27 and SATURATION: 40

Final Result here: