Which kinds of decorations did artist use on Tutankhamens mask?

They used gold to decorate King Tuts Mask

The King Tut Mask weighs ten kilos, 24lbs and measures 54 cm (21 in) in height and 15 inches wide. The workmanship is quite exquisite and its value is priceless. It is made of gold which is inlaid with semi-precious stones, coloured glass paste and the eyes are made with obsidian and quartz. The back of the mask is chased with a series of spells and texts from the Book of the Dead. The mask was placed directly on the mummy of King Tut inside the third coffin housed in the sarcophagus. The death mask of King Tut was not made of gold just as a sign of the immense wealth of the pharaoh. Gold was also believed to have a magical potency containing significant religious properties. Gold did not tarnish or deteriorate. But more importantly gold shone like the sun god and was therefore credited with the powers of the sun god. Gold was therefore referred to as the 'Flesh of the Gods'. This explains the use of gold in the artefacts found in the tomb of Tutankhamun including the King Tut mask.

The design depicts the traditional nemes headdress. The nemes was the striped head cloth which would have been worn by the Pharaoh Tutankhamun. The nemes was worn tight across the forehead and has lappets falling forward over each shoulder. The top of the nemes displays the uraeus and the vulture on the brow. The uraeus was a rearing cobra emblem associated with the "eye" of the sun and meant to protect the pharaoh by spitting fire at his enemies. The cobra snake and the vulture were emblems of the deities Wadjet and Nekhbet. The goddess Wadjet was the patron goddess of Lower Egypt and was associated with the land where the cobra was present. The goddess Nekhbet (the embodiment of Hathor) was the patron goddess of Upper Egypt and was associated with the vulture. These two goddesses were together known as the 'two ladies of the pharaoh' whose special purpose was to protect the Pharaoh. The figures of a vulture and a cobra therefore sit on the king's forehead on the nemes headdress. The headdress has yellow stripes of solid gold, broken by bands of glass paste, coloured dark blue imitating lapis lazuli.