Making Metal Reflections
Open a photo that you you want to add some pizzazz to. I am using the photo below I got from http://www.pbase.com.

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. Create another selection, this time on the right side of the left guitar:
Follow the bulleted list above to apply a gradient to this part of the guitar. Continue selecting parts of the guitar you want to highlight. Make sure to deselect your selection after you finish the gradient drag.
Now switch the color palette so that the light color appears as the foreground and the darker color appears as the background. To do this simply click the arrow between the foreground and background color
. Choose the gradient tool, setting is option to Foreground to Transparent and linear:

Create a new layer. Choose the brush tool
and click on the Brushes drop-down box in the Tool Options Bar. Click the Brushes pop-up menu button and choose Load Brushes from the fly out menu.

Choose Assorted Brushes. This load the Assorted Brushes palette ready for use. Click the Brushes drop-down box again and choose Crosshatch 48.
On the new layer, click with the Crosshatch Brush a couple of times where a natural highlight might occur.

Change the brush size of each for a more natural effect. Here is my finished product:
