I have never had the chance to work on a model from scratch other than the clone wars cartoon Obi-Wan me and Psykosith worked on. Everytime a model is coming out that I want to skin, the author never seems to e-mail me back with a chance. SO I wait until it's releaased and skin my own version.
On the skinpack, most of the textures I made are from scratch. (IE: the faces, hair, and parts of the robe.)
As far as the rest of the parts, I've noticed that when making a reskin, it's more efficient not
to change current textures if they don't need it, but rather just tweak
the existing ones to your liking.
IE: Marz's Anakin- I re-did the face, hair, and leather from scratch, The robes and boots I left alone, but tweaked them using additional textures and lighting.
I also have some original skins that I made from scratch here: www.geocities.com/omeewan
I was working on a cel shaded comic book star wars mod, (it looked like the windwaker and XII)
And also some samurai/ninjas.