Once upon a time there was a woman named Eve living in the Garden of Eden. She was naked. One day a serpent convinced her to eat from the Tree of Knowledge. Suddenly she realized that she was not at all tznius. She went and sewed herself a skirt. Unfortunately, upon trying it on, she realized that it did not fully cover her knees while sitting! So she went and found some more fabric and added a couple inches to her skirt. Now it was time to work on a blouse. Not having learned from her mother, Eve had trouble making sleeves that would never ride up beyond her elbows. Finally, very proud of herself, she finished this too. Unfortunately, upon looking in a calm pond, she realized that her blouse was much too tight! Unhappily she went back to making a more tznius blouse from scratch. Just as she finished putting her new blouse on, Adam walked into the room (it was halftime in the Jets game) and said, "Wife, what is there to eat?" At that moment Eve remembered that she was married, so she was required to cover her hair! Frantically she ran back to her pile of sewing supplies and dug through it until... at last! A snood! All was good. Her hair was covered, her knees and elbows hidden, and none of her clothing was too tight. She was dressed totally tzniusdikly, just like the millions of holy Jewish women who would someday be descended from her.
Actually, while this makes a good story, things in fact happened differently. Eve actually put on exactly the same clothing Adam had - a girdle or loincloth around the waist. The only "real" halachic nakedness, I think we learn from this story, is the genitals. The rest is just societal norms. Clearly women as well as men today should not be walking around in loincloths. But just as clearly, we should be aware of where our halacha comes from.