I have this idea that I have seen implemented with great success in other games, both in the MMO genre and in more traditionel games.
Basically I would love for a Barber to be introduced to the world, it would not break lore or unbalance the game in any way and it would give us the players a place to thrown gold at for a new haircut, new facepaint/makeup and such.
Now I would also suggest that there were an option to cut a "secret" deal to go into the backroom "basement" or whatever.. it could even be a portal to a pocket plane in a backroom, where you cut a deal with a daedric lord to give you a complete custom overhaul... If you feel this is not in lore with barbers it could be a thief guild thing.. something along the lines of wanting to change identity :P .. Anyway that more comprehensible makeover could easily cost crowns like the scrolls you buy for XP.
I believe there would be a big market gold and crown wise for this feature. I know I would love to pay crowns along the line of 1500 -2500 to change some things about my character like the Voice, and perhaps give it a more "heroic" rugged face since it has been in Tamriel for a while now and shouldn't look like such a "soft" featured person
Anyway I hope to see this feature.. I have never seen it not be a success in games + it would boost your Crown sales which makes more money for you guys, so it's a win win as I see it