In the class we talked about what an apron of fig leaves would be like. The word translated as "apron" in Hebrew is חגרת and everywhere else it appears in the Old Testament it is translated as a "girdle". When it occurs in 1 Kings 2:5 it specifically is worn "about his loins". So it sounds like a wide belt or loincloth. How effective would a loincloth made of leaves be to cover nakedness? The answer is, not very effective, and these are some reasons why:
1. Fig leaves, though fairly big, have finger shaped lobes instead of being solid. It would be different to overlap them in such a way that there would be no gaps/holes.
2. Fig leaves contain a natural poison that can give people rashes.
3. Fig leaves would dry up and become brittle after just a few days.
The message here is that fig leaves are not a good choice for covering you. They are ineffectual because of their shape, poisonous, and temporary. (note, I didn't know until this week that fig leaves gave you a rash, but the people of Israel would have known because they grew a lot of figs. I could imagine everyone in the audience of an ancient synagogue cringing when they heard of a loin cloth made of fig leaves.)
After Adam and Eve confessed their sins, God made them a better covering, a coat of skins (Moses 4:27). How is the coat of skins better than the fig leaves? It is much more permanent, durable, comfortable, and effective. Yet, to make the coat of skins required the sacrifice of life. The symbolism is fairly clear. In order to cover Adam's sin in a way that would work and would last, a sacrifice had to be made. In the story it was the sacrifice of an animal, but symbolically it represents the sacrifice Jesus himself made to atone for the sins of the world.
The word, atonement, does not appear in the New Testament, but it does appear in the Old Testament in relation to animal sacrifices. The word for atonement used in Leviticus 17:11 and repeatedly in the Old Testament is כפר. It also mean "a covering." (it is used to describe the covering of pitch that Noah put on the ark) So when God makes a coat of skins for a covering, that passage could be translated (if we had it in Hebrew, but we don't since it is from Moses, not Genesis) as "God made a coat of skins as an atonement." The atonement is the only durable, effective, and non-poisonous way for us to do away with the shame and fear associated with sin.
So we have a choice, we can try to cover our own sins with a loin cloth made of fig leaves i.e. by hiding, justifying, or blaming, but none of these fixes are permanent, comfortable, or even effectual. The only true way to rid ourselves of the shame and fear resulting from sin is to accept the Lord's covering, his atonement. 
