The first and most common key accessory belonging to the late middle ages period is the amonieres sarrasimoises or Saracen almsbags. These were the ancient version of the modern belt bags. The almsbags were multipurpose and they held anything from money, to food (to pass to the poor), or a bible. These were made of silk and leather and were thematically embroidered. Both men and women would use almsbags for whatever purpose they needed it.
Headgear was an interesting combination of subtleties and exaggeration. Some hats were pointed, huge and asymmetrical. Royalty wore circlets, or bands that would go around the head with circles as decoration. Women who wore the hats would put their hair up. Women who wore circlets or even coronets (aristocrats) would create an illusion of really long hair that would be sleeve length. The tunic fashion of the time also called for long sleeves in tunics, so the image would seem almost ethereal. Unmarried women and young girls likely adopted the same style since they also wore their hair long and lose. Movies such as Lord of the Rings use the motif of the Late Middle Age, particularly the lose hair/circlet style.
Two odd pieces of headgear were the the crespine and the side caul. These were extensions that go sideways or in a horn. This made the hair look rectangular. They became larger and larger with time. In the movie Star Wars Episode One the character of Queen Amidala is featured wearing a caul that followed the style of Late Middle Age as well.
Men's headgear was also used depending on the guild that they belong to as workers. Lawmen were known to use black hats and apprentices would use a cap. The issue for men was that, if their hair grew too long, they were looked down upon. If they cropped their hair then they would pass as clerics. Hence, men ultimately chose their own hairstyle as long as they differentiated themselves from clerics by their wardrobe.
As far as jewelry, the fashion was to follow the lapidary, which is a treaty that claims that jewels had magical powers. Hence, it would not be surprising that those who could afford it would wear gold rings, or bronze plates featuring the stone of their choice. Therefore, this would be a practice that both genders would follow.