That's because it's not done that way. It's done with software tools like: http://www.virtual-cover-creator.net/ Didier
One of the best template-based scripts I've seen to make such covers is for PhotoShop. You can see it here.... http://www.coveractionpro.com/
yes, people. the software recommended by DidierE and Knightme are well worth a look if you're thinking of making your own ecovers.
Oh wow, those are absolutely stunning. Nice colours; extremely neat and clean-cut. Perhaps the bar code could go on the back of the book, though.