learning how to skin

If you can already make the graphics and just want to learn how to piece together a skin, the best way is to download someone else's, and fiddle with the inner workings of it. Look at how the graphics are made, the settings used, etc. If you need to learn graphics better, read as many tutorials you can find. A good place to start is this thread from the Skinning section. https://www.wincustomize.com/msgboard.asp?BID=WCS&id=165295

I know how to skin a catfish

You might want to look up and click on the "help" or "skinning" discussions.

Play with something easy first and learn from there.