Ligurian sorcery is primarily practiced by Gigantes spellsligers living in the Titanomachy. It lends itself particularly well to enchantments and is without peer when it comes to large workings however it lacks breadth and flexibility of Trismegistan Sorcery.
The Ligurian theory of magic is speculated to be the oldest comprehensive framework for using the Gift, though Masego does mention it contains a lot of unnecessary elements. It's well suited for spells with large effects. Antigone's battle with Warlock resulted in large pieces of the mountain range getting destroyed, the spellsligers managed to defeat Ashuran fleets by using their sorcery and their duel with Dread Empress Triumphant resulted in a giant lake known as the Titan's Pond.
The theory has heavily influenced Proceran traditions though it's rare to see it used by humans. Both Hanno and Warlock remark that the Witch of the Woods is not a true spellslinger because her understanding of Creation is not on the same level as that of Gigantes. Indeed, it seems like a deep and intuitive understanding of Creation, known to Praesi as the High Arcana, is a prerequisite for practicing this sorcery. 
- "The Witch had not spent centuries permeating her body with the light of moons and stars, woven a second soul out of sunlight or aligned herself with the celestial spheres. She could not sing hymns to the world and make it dance to her will. Instead the power of her aspect flared, and for a moment she was one with the fabric of Creation"
- ―Hanno of Arwad
It has two signature elements. The first is known as the Creational cascade - a release of power into the world that accumulates ever-deeper orders of effect. It often uses guiding elements such as 'songs', which are in reality an exquisitely complicated verbal control techniques.
Beyond mighty spells, Ligurian sorcery is also known for its enchantments. We've seen three examples of their work in this area so far.
Red Snake Wall
Built by the titans, the Red Snake Wall protects the Dominion of Levant from a Proceran assault by land. It stretches for many miles, from the sea to Brocelian Forest. The foundations of the wall are only ten feet tall however they support a giant, granite red snake that is enchanted to eat whoever seeks to pass it. It's considered the biggest enchantments since the Miezans were on the continent.
Chamber of Borrowed Lives
Located in the Titanomachy, this chamber allowed Hanno to live through countless other lives of other heroes and probably led to his first Aspect, Recall. Exactly what this enchantment does or how it is achieved is not explained.
Hanno’s Shapeshifting Weapon
Usually employed on the sea, this spell has been used to control large bodies of water into whirlwinds and direct them according to the whims of the caster. Witch of the Woods managed to use it on a lake burning with goblinfire.
Riddle of Kreios
Envelops the target in a bubble of accelerated time.
Kronia’s Sickle 
Another spell dealing with time, though in a different manner to the Riddle of Kreios. Effects unknown.
Currently, the only human practitioner of the Ligurian sorcery is Antigone, the Witch of the Woods. Presumably there are many more Gigantes spellslingers in Titanomachy however the nation is not involved in the Tenth Crusade and we've not seen them in the series so far.