How to keep children from obsessing over their appearance

Find me a young actress who does NOT have plastic surgery or shed half
her body weight after makin' it big, and I'll find you the face of
Jesus in my next bowl of oatmeal.  Personally, I don't really care
whether Mary Kate and Ashley are small enough to squeeze inside a piano
bench during their next game of a hide and seek.  What I do care about,
however, is figuring out how to raise self confident children in such
an image conscious world.  What are some steps you think parents should
take to help  their kids focus on the playground instead of their
looks?