Follow the sun. It sets to the west. Either way,I would possibly need shelter,so I would look for moss and fallen trees for protection from the elements and wait til dawn for the trek back. The typical yahoo answer? "Leave a trail of crumbs"
oh, I was going to say, "pull out my iphone and use GPS" But I guess I would have wait until dark so that I can get my bearing via the stars. I guess it pays to study astronomy.