I just wanna share a simple effect na i love doing!
Create a new document using the Default Photoshop Size and apply a Clouds filter (Filter > Render > Clouds).
Use the Motion Blur filter (Filter > Blur > Motion Blur) to apply the following properties:
Angle: 0º
Distance: 150 pixels
Click OK.
Use the Add Noise filter (Filter > Noise > Add Noise) to apply the following properties:
Amount: 5%
Distribution: Uniform
Monochromatic: Uncheckmarked
Click OK.
Use the Motion Blur filter (Filter > Blur > Motion Blur) to apply the following properties:
Angle: 0º
Distance: 10 pixels
Click OK.
Create a new layer and apply a Clouds filter (Filter > Render > Clouds).
On the current layer, use the Brightness/Contrast tool (Image > Brightness/Contrast) to apply the following properties:
Brightness: -25
Contrast: 50
Click OK.
Add a layer mask (Layer > Add Layer Mask > Reveal All) to the current layer.
In your new layer with Clouds Filter and layer mask, use Hue/Saturation tool (Image > Adjustments > Hue/Saturation) and apply the following properties:
Hue: 10
Saturation: 70
Lightness: 0
Click OK.
Still at the cloud thumbnail, Use the Add Noise filter (Filter > Noise > Add Noise) to apply the following properties:
Amount: 5%
Distribution: Uniform
Monochromatic: Uncheckmarked
click OK, and then, Apply Motion Blur Filter (Filter > Blur > Motion Blur) to apply the following properties:
Angle: 0º
Distance: 30 pixels
Click OK.
Change the layers Blending Mode to Overlay
Click your layer mask thumbnail, use Brush Tool (B) set to 250px and with 50% opacity, start brushing away rusted parts from the layer to create a group of tiny speckles of rusts in your metal. Make sure that your foreground color is set to default (or black).
There you have it, after being flattened out, this trick can be used as a background or a text effect. Enjoy!!