IDEA Stone 'Sakkunskap'
With a little assembly (and a quick trip to Gnome Depot to replace the missing screw), you can get one of these enchanted stones to orbit your head and improve your skill at pretty much everything through 'positive radiation'. Unfortunately, due to cheap materials, they can be broken.
While attuned, you can use an Action to throw the stone into the air and have it orbit your head. It will orbit your head 1' out and is considered to be worn while orbiting you. The stone has an AC of 24, 10 HP, resistance to all forms of damage, and can be snatched mid-orbit by a DC 24 Acrobatics check. While orbiting you, this stone increases your proficiency bonus by 1.