[MLD-Grounds-Keeper-Willie]

I think that elves just show age through how much they know and in their eyes as raefindel said. Now besides knowledge, wisdom, and their eyes, I think that they do not show any physical aging. They are not supposed to look old. The way tolkien describes them makes the elves more of a mystery and shows how complex they are. I think that if they are not 100% elvish, that might have some effect on their physical appearance but not too noticeable. I think that maybe since Elrond was so wise it would make him appear to look older but since he is an elf, in stead of looking young, he looks neither young nor old.