yeah, skinning is a very different beast, since there isn't a way to upload graphics, and so to get results that you want you have to think about everything in is base geometric shapes...
lets use the last skin i made as an example...
the birds are just one of the fonts. i took one of the lower case V shape and stretched it until i got a look that i liked.
the fish are similar, but a little more involved. are made up of 5 shapes
a set of parenthesis put together to make the body shape ()
an ampersand to make the tail &
a circle shape stretched into an oval to fill the body in
and then a gradient circle shape stretched into an oval to give a some dimensions to the fish bodies.
the clouds are basically just a whole bunch of gradient circles on top of a circle stretched into an oval to give the cloud a flat base.
and finally the mountain is a triangle with a couple of tear shapes on the edges to make it look more like a mountin, and then a couple more tear shapes on top of the triangle to give some more detail to the mountain.
hope that helps.
if you want to gift me a sprinter trueno, i'll put this skin on it and gift it back to you so you can look through all the labels to see how i accomplished everything if you'd like. i should be able to stay online long enough to be able to do that.