Skinning tutorial request

[major_setback]

Thanks for the information. I have a couple of questions. I am very grateful if anyone could answer these:

What sort of compression should I use on the finished skin when compressing the psd layered file to jpeg? Highest quality?

I have seen layered skins (layered templates) with a separate weather/panel-lines layer. Have these come from a layer within the default skins, or have skinners created these themselves? If they are in the default skins then how can they be extracted? I only see jpegs in my skins folder, not layered psd files.