These are photos of antique outboard boat motors. I applied an over-sharpening effect in Photoshop that really brought out the patina in the metal. This effect will not work for too many photo subjects, but for aging machinery, it can be a lot of fun.

Create this aged looking effect by combining this photo,

and this texture.

Here are the steps:

1. Put the texture in a layer above the photo.
2. Change the texture’s blend mode to something like “vivid light” or “overlay” depending on your preferences, and drop the opacity somewhere between 15 and 20.
3. Add a slight blur and vignette to the edges of the photo.
4. De-saturate the colors a bit, drop the contrast, and shift the color balance toward yellow.