Start a new document I used size 400x125px and fill it with white. Then find a nice picture or render. Then pick the stamp tool (near the history brush tool) and chose a brush then press Alt and click on a place that you like. Then click again with the brush before you clicked with a circle, I did this. (Be sure you have both pics on RGB colors).
Then go to you're new document and click with the stamp tool on the white background I got this:
You can use every time other brushes and other places from the pic or just use other pics if you want to. Now continue this till you're background is filled like this.
I'm sure you can do it better then I do but anyway now you can use patterns on it or what I like is using the picture you used with the stamps in your new document, like this. Btw this is all to yourself.
I think we just made a nice background don't you?
More Tutorials: 
