You wait for years for another book on Icelandic Sorcery and then two come along.
In chronological order:
Icelandic Magic: Aims, Tools and Techniques of the Icelandic Sorcerers, by Christopher Alan Smith, http://avaloniabooks.co.uk/catalogue/norse-viking/icelandic-magic/
Previous to this, the only material in English on Icelandic magic and my first taste of its magical syncretism had been Stephen Flowers' The Galdrabok, in 1990. (https://www.amazon.co.uk/Galdrabok-Icelandic-Grimoire-Stephen-Flowers/dp/087728685X) .
This book is a thorough and very readable survey of five hand-written manuscripts, personal books of magic, giving us a glimpse across time, from the 16th to the 19th centuries, of a whole tradition of magic which still feels alive today. One of these volumes Christopher Smith translated himself.
'Aims, Tools and Techniques' provides rich backgrounds to the folk-magic - the material history, the religious shifts and persecutions, which are interspersed seamlessly into the exposition. The spells themselves range over the usual human preoccupations, particularly in a poor and pressured community, and are categorized into ten main categories, with careful consideration of the distinctions between 'white' and 'black' magics. The text and presence of the material is made more vivid with facsimile insets of original manuscripts.
I was honoured to read Chris Smith's book when it was in the version that became his Master Work of Rune-Lore for the Rune-Gild. One of the vital functions of the Gild is to nurture, encourage and challenge people to give of their best in what they write and produce, thereby helping light the way into Germanic esotericism. Such documents form lasting monuments to the author's personal quest. Chris Smith's book is one such.
The head of the Gild in its present form has added another stellar book to his long list of essential reading for anyone who wants to look seriously at the Northern Tradition.
Icelandic Magic: Practical Secrets of the Northern Grimoires by Stephen E. Flowers, http://www.innertraditions.com/icelandic-magic.html
His Galdrabok contained enough magical detail for an experienced wizard to build a few rituals; Icelandic Magic is a full-blown practical grimoire. Historical perspectives and an underpinning of the kind of confident and precise exposition of magic only a seasoned magical teacher can offer, build a solid base for the grimoire section. Thorsson declares:
'What you now possess is ... a genuine book of magic and should be treated with reverence to ensure that it maintains its magical essence.'
Then we are treated to some very interesting tales of great Icelandic wizards. These were men (most victims of witchcraft trials in Iceland were men) of widely differing reputation, and this section gives us food for our imaginings of what it is to practice magic, what kind of being we might become.
The grimoire from which the spells are taken is the famous Gray-Skin. The extensive appendices include tables of runes and rune kennings. The usual range of spells is present in the grimoire lists, but the way Thorsson expounds magical practice makes 'Practical Secrets' a unique volume, not a mere collection of spell-recipes.
I can unreservedly recommend both of these books to serious students of Northern magic.