Traditionally the Grand Master of the Aurum Solis has the titles "Druidic High Priest of the Celtic Mysteries of the Aurum Solis" and "Guardian of the Order of the Green Flame of Albion" (also called the Order of the Green Flame - Lasair Uaine). 

At the beginning of the Aurum Solis, the Order based much of its work on Celtic rituals and practices: the ancient Fire Festivals, Imbolc, Bealteinne, Lughnasadh and Samhuinn. These rites were celebrated year by year.

Incidentally, several Grand Masters played an important role in the revival of Druidism. Thomas Maughan was Chief Druid of England in the Druid Order and his role has been very significant. He taught the current head of this Order, David Loxley.
Vivian Godfrey was one of the founding members of the "Order of Bards, Ovates & Druids" in the 1960s. When she returned to Britain in 1989 after spending some years in the USA, she was invited to succeed John Michell as Presider over the same Order she had belonged thirty or so years previously. Godfrey presided over this Order until her death in 1997. 
The current Grand Master Jean-Louis de Biasi, was received in the Druidic Tradition in the 80s in France. Then he was initiated in various shamanistic lineage that were later associated with the Celtic and Druidic tradition of the Aurum Solis.

Shamanistic rituals are a fundamental part of Theurgy practices. Using ancient musical instruments, dances, breathing techniques, trances, and out-of-body techniques, the initiate is able to travel in the spiritual world. These individual and group rituals are even more ancient than the Celtic civilization. They can be traced down to prehistoric times, and the most secret rituals practiced today continue in remote places such as caves and mountains.
As in the beginning, this Order constitutes one of the most important parts of the Aurum Solis Tradition. 

The Order of the Green Flame, which celebrates pre-Christian, Celtic, or Druidic feasts, is under the direct authority of the Grand Master and only this individual has the power to authorize their use. Whenever these rituals are used in the Aurum Solis, they must be preceded by the Rota Fulgens Solis rite, exclusively reserved for this purpose. 
The eight ancient Festivals are still practiced within the family of the initiates of the Order, in the presence of their spouses and children. Other rituals are practiced only in an Aurum Solis group or during a seminar of the Order. However, initiations based on the most ancient rituals are rarely practiced. They are proposed and conferred only by the Collegium Cathedrarum and constitute one of the most secret and advanced rituals of the Order.

The Order of the Green Flame is not accessible to the public and is restricted to the initiates of the Aurum Solis de facto members of Stella Gloriosa and in part to their family.