There are many different kinds of Elves, and I can speak only for the ones I remember, so please don't assume that I now speak for all Elves! We bore some similarities with the Elenari, particularly with the sub-group known as Listari, but a definite correlation is not confirmed. One of my kin started using the word "Eldar" to refer to ourselves, and we mutually agreed "Eldari" as a compromise. The world we remember was named "Land of Song" and the word I recall for this is "Alorya". I shall continue to use these words in this essay.
Physical Description: The Eldari are tall (6"-12" taller than humans, as far as I can tell) and slender with a wiry build and angular features. The complexion is pale, hair colour varies but black, blond and silver seem to be the commonest, with a few red-heads (but I recall none with brown hair). Long hair was favoured by males and females, and soldiers woud wear it in a braid. I don't remember pointy ears. It sounds like an insult to me... :)
We had a very long lifespan, about ten times the average human's, so a typical Eldari would expect to live about 700 years. Childhood was probably not much extended though; I seem to recall that physical maturity was reached at about 25 or so. We do not die of disease or old age; a natural magical resistance to such things, combined with powerful healing magic, sees to it that there are no serious diseases among our kind. Accidents and acts of violence still occur, but again a high degree of healing magic ensured that fewer injuries proved serious. However, when we reach a point in our lives where nothing more can be learned or achieved, then we make a conscious decision to bring our physical lives to an end, in preparation for a new cycle to begin again.
Families: You might expect that with such a long lifespan, there would be an excessive population, but this was not the case. The birth-rate was slow; so slow in fact, that the population coud not be maintained, and in the time-period I recall, we were in decline, a race in the twilight of our time. Few Eldari had children (though some who did were excessively blessed!) Twins were more common than they are among humans. As a result of this difficulty to concieve, children were considered extremely precious.
Because of this, our relationships are, mostly, not formed for the purpose of childbearing. So from my experience I have found that Eldari have several intimate relationships, and there is a tendency towards bisexuality as well (though not among everyone). A sexual relationship is a bond of mutual respect and companionship, and is not intended to infer exclusive posession of a partner.
Lifepaths: Another result of extreme longevity is that we will often feel drawn to make changes, in some cases drastic ones, in the direction of their lives. As an example, I myself, on reaching adulthood, first underwent many years training in magic and I spent some time working as a healer. After I grew tired of that I became a travelling bard, accompanying another; we travelled the length and breadth of the land, entertaining in taverns for whatever hospitality was given to us in return. After the untimely death of my partner I settled down again, this time with the military, and I became a soldier.
Such changes in career are not made on a whim but as a result of a calling. This is sometimes preceeded by a prolonged feeling of dis-satisfaction which was called the Yearning. This manifests as a restess desire for something you cannot name, and there is usually then a period of wandering, rather like the concept of "Walkabout". During this time, the Eldari wanders, seemingly without purpose, until the feeling subsides and he or she is able to settle again.
Religion: I remember a religion, but I don't know to what extent other elves in my homeland followed the same religion. I think it might have been a very old thing which had all but died out. Basically we "worshipped" (though I don't think that's quite the right word) a creator-god(dess) who most commonly took the form of a large dragon. I don't remember any specific ceremony but I certainly remember praying to Hir, and swearing oaths in Hir name. The creation-myth connected with this goddess tells that Sie created the World with hir song; sie literally sang the magic that brought the world into being.
There was also another religion which was more widespread. There were no deities in this one, but a belief in a pervading spirit or essence in all things. There was ritual in this religion, and I find it hard to find the line where the religion ended and the practise of magic begins. It was rather like country-witchcraft, with a strong reverence for the natural world. I think I personally practised both.
Magic: We are a highy magical race. Magic seemed to be integrated with daily life, indeed with our very being and existance. I do not recall much in the way of ritual though I know that some magic was ritualised, allowing two or more people to work together on the same thing. Mostly, magic happened on a more intuitive level, and was less structured. There was an extensive Royal family in Alorya, and there was the feeling that the more closely related one is to that family, the greater the potential for using magic.
Political Structure & History: Alorya was ruled by a high king, who was among the more prolific Eldari, having at least 5 children, and probaby more. Succession was not necessarily from father to son, but could be conferred on that person whom the King considered to be the most worthy.
Below the King was his chief advisor, who was a cranky old wizard. And below him was a council of elders, comprised of other mages, scholars, military leaders, and heads of local communities. The council was inaugurated many millenia past, for the purpose of protecting and defending Alorya from outside threats.
Another purpose of the Council was to regulate invention and technology. It was known that unfettered progress would cause ecological damage to the environment so such advances were carefully controlled. There were magickal Gates which allowed travel into other Realms so there as a great deal of trade and interaction with other races (in some cases, more technologically advanced ones). The council ensured that any alien technology brought into Alorya was safely confiscated (though rumors abounded that the Council were secretly using such technology for themselves).
There was also a military force called the "Elite Guard" who were partly soldiers and partly rangers. They operated in units of five, known as "Hands". Part of their responsibility was to defend the Royal Family, but they were also responsible for defending Alorya against invading enemies, particularly those which might enter through the Gates.