Ok, here we go. I apologize for the delay in getting done with this.
I did the process two ways in the attached PSD. On the upper elevator, is the quick easy way. Just some shader lines, and with different transparency, as I mentioned before. The more difficult method is one I used on my skins, and is shown on the lower elevator. Each layer is named to make it clear.
Hope this is helpful, if you need more guidance on it, please post back!
