I figured since it's getting close to the Winter Nights portion of our year, I'd throw out some chewing stuff on Álfablot... which is one of the few literally documented sacrifices that at least some of our ancestors held. Álfablot was a sacrifice to appease harmful álfar or to give "gift for gift" as thanks or to request healing or other benefits. The earliest secure reference to the custom is in "Austfararvisur" (Verses on a Journey East) written by the skald, Sighvat Thordarson to commemorate a journey to West Gautland in the autumn time of 1018. Interesting enough, is the fact that there are lines indicating that he was refused entrance into numbers of hearths because of the sacrificial ceremonies going on to the álfar:

"'Come in no further,
wretched fellow', said the dame,
'We're heathens here;
I'm scared of Odin's wrath.'
The grim crone that checked me,
firmly, as if I were a wolf,
said that inside the house
they were holding elf-sacrifice."

To judge from this stanza, and of course the proceeding stanzas, the same ceremony was taking place in more than just one household. Being that Sighvat was a Christian, the timing of it was unfamiliar to him, though that may have had more to do with regional timing, unless he wanted to distance himself from these "heathens" he met in his literature, as many tired to do at his time.

Another reference to Álfar sacrifice is in Kormak's Saga (around the 13th century) in which a seer woman instructs a man Kormak wounded before going to sacrifice a bull. His wounds are taking too long to heal:

"There is a mound not far from here, where the elves live. Now get hold of the bull Kormak killed, and redden the outside of the mound with its blood and make a feast for the elves from its meat. Then you will be healed." The cure, according to the saga, works.

The Álfar come in several different types. They are the Ljósálfar (Light-Alfs), the Døkkálfar (Dark-Alfs), and there are the Svartálfar (Black-Alfs).
The Ljósálfar are those who inhabit Ljósálfheim, which is said to be ruled by the Vanic god, Freyr. Most modern Ásatrú just refer to it as Álfheim. The Ljósálfar are thought of as being divine/semi-divine spirits of the air and brightness. They are described as being very bright and beautiful. It is an extreme rarity that human beings would encounter them.

The Døkkálfar, or Dark-Alfs, are what most modern Ásatrú are thinking of when they refer to the "Álfar". Sometimes referred to as "Mound-Alfs", the døkkálfar are divine/semi-divine entities which were once either male ancestrial spirits or wild beings which live in wood and stone in Miðgarð. The male ancestrial spirits are humans who, after being put into their mound, became attached to the land, or the people nearby and have turned into protective spirits. The "wild" Dökkálfar who live in stones and trees or other wooden structures seem to be something akin to the Landvittar. Those are the "Álfs" in which may sometimes be hostile to humans and inflict them with "Álf-shot" and make them mysteriously sick when offended. These types of Álfar are described as being either darkened in skin or pale like the dead.

The Svartálfar, or Dvergar, are what people commonly refer to as Dwarves. They dwell in Svartálfheim and are great craftsmen and smiths. They are described as being dark in complexion and will even turn to stone if exposed to sunlight as told to us in the eddic poem, Alvíssmál. They are the beings which created many magical items for the gods and men of Miðgarð. Another thing to mention is that there are human beings which are said to have turned into Svartálfar, like Reginn of the Volsung Saga.

This all sort of brings us into the modern concepts of the Álfar. How do we envision them? Do we honor them enough? It's good to "re-connect" with the gods, but what of the other "divine/semi-divine" beings that inhabit our metaphysical worlds? Like the different Álfar, the Tomten, the Landvittar, the Dìsir, and even our own personal ancestors?