first, is this seidr? Seidr Craft:The true art of Seidr lies in the ability to create shapes in your head and impress them on the outside world.
I don't think so...
Freyja was originally the norse goddess who used seidr. This site seems closer to the mark, but still confuses some of the basics: Freyja as her brother Frey is though to have originally been a fertility goddess, but there are no sources suggesting that she was called on to bring fruitfulness to fields or wombs. She is rather a goddess of riches, whose tears are gold and whose daughters are precious objects. Freyja taught the gods to use seidr, magic.
no, she only taught Odin seidr. she taught the rest of the gods the charms and spells of the Vanir, which isn't the same thing at all.
seidr then appears to be intimately bound up with both the shamanic initiation both freyja and odin undertook, and to be tied directly into sexual magic.
jodie forrest's article on freyja seems to come closest: Freyja was the patron goddess of the Norse seers called volvas,or seidkonas, who practiced a form of magic called seidr. Seidr means 'spell' or 'enchantment', and also,'boiling' or 'seething'. It could include sex magic, prophecy, shapeshifting, sendings, curses, fettering opponents, communicating with Elves or the dead, healing, midwifery, vision quests, giving council, and the use of spirit animals... Seidr, however, was mostly performed by women. Odin was the only god who practiced it, and, again, he learned it from Freyja, acquiring traits that were perhaps originally hers.
I started wondering about this when I tried to figure out if frey & freyja correspond somehow to the kaos-babalon/156 current. In fact, near as I can make out from the eddas the only male to use seidr is odin (then again I don't read norse, just translations and myth stuff)
personally I suspect seidr was a masturbatory practice using various substances coating a dildo or buttplug while laying on a high platform - which would account for snorri's note on seidr where he says "the use of this magic is accompanied by so great a degree of effemination (ergi) that men were of the opinion that they could not give themselves up to it without shame, so that it was to the priestesses that it was taught" (source)
you get that? seidr isn't another name for shamanism or the underlying magical paradigm of chaos magic.