Result:
1. Open up Photoshop, and pick your Paint Bucket Tool (G). Change from foreground to Pattern and pick your Horizontal Warning Stripes. If you do not have this pattern, you can download it here
2. Next paint your canvas with the Warning Stripes pattern and go to Edit > Transform > Skew. Now skew the pattern to the left or right, it does not matter.
3. Now after you have skewed it, time to make it all fit in the canvas. So go to Edit > Free Transform, or press ctrl + t. And make it fit on to the screen covering the whole canvas completely, like the following screen shot:
4. Now its time to get dirty, so make sure you have some grunge brushes downloaded, if you want some (also some of the ones I'm using) here are some links:
Anyways, now back to topic, Get a grunge brush and make a new layer, change your foreground color to #855d00 and start brushing up the image don't go too much just a little here and there and don't brush over a spot you already brushes with, also don't brush with the same brush too many times. Here is what i got after this step:
5. Next make a new layer and change the foreground to #b5910d and change the blending mode of the layer to Linear Dodge. Now using a different type of grunge brushes, start brushing a bit more over the spots you didn't brush before, remember not to over brush.
6. Now make a new layer, change foreground to #604200 and change the blending mode to Multiply and brush up a bit more.
7. Now make another new layer, change the foreground to #7c6228 and change the blending mode to color dodge and start brushing more and make the opacity 80%.
8. Make another new layer, change the foreground color to #806c00 and change the blending mode to Linear Dodge and change the opacity to 70%, now start brushing more.
9. We're almost there, and its coming together, make another new layer, change the foreground color to #b19501 and change the blending more to Soft Light and start to brush more.
10. Last step and your done! Choose brushes that are cracks and have scratches in them. Change the foreground to #605100 and the blending mode to Soft Light and now start brushing. Don't brush too much here because you should be using the brushes in the steps to make scratches and cracks.
This concludes our tutorial, you should have something similar to this:
Examples of what you can do using this tutorial:
