Focus Items

Introduction

Focus items is a rather general magical term that's covering two main things: a certain form of magical jewelery and a rather crucial part of most rituals, especially those performed by the cultists. In both cases, the underlying nature is the same - an object attuned to the particular magical frequency/nature of a single Power.
They have a variety of usages, and are considered a crucial part of generally understood artificing.

Creation

Focus items can be created in two ways - through artificing or through rituals. The former requires application of appropriate paramaterials, with at least a hint of intent of creating an appropriate focus item. For example, an ring made of hardlight will, undoubtedly, become a focus item for the Ancient of Days.
The ritualistic way doesn't directly imply performing any rituals over the item in question (although that's an option too). The proper ritualistic way of creating a focus items works by taking a preexisting item and using it purely (or almost purely) in a way agreeing with the principles of a Power in question. For example, you can expect a surgeon's scalpel that was used to perform body-altering surgeries (especially plastic ones) to qualify as a focus item of the Ancient of Flesh.
It is thus generally believed that it's hard to find a used object (especially an antique one) that isn't at least technically an extremely weak focus item of one Power or another, however most of them will have their effects too weak to be noticed in practise, and their nature can only be detected through detection magic.
This can be weaponized - for example, it'll be extremely hard to find traces of magic of the Lore of Flesh in the middle of a hospital, due to the sheer number of Lore of Flesh focus items literally everywhere around you.

Function

Focus items work by acting as an auxilliary form of raising attention of Power that they are dedicated to. This is a double-edged sword for a mage. While carrying powerful focus items makes appropriate magic stronger, it also amplifies the attention level. While the additional attention goes away when the focus items is put away, this basically means that each time there is even a slightest risk of going demi during the cast, you'll find it more likely to happen.
For cultists, however, the focus items are incredibly beneficial. Since most of their craft is about raising their collective attention level, you can expect them to hang around places with as many powerful focus items as possible. They avoid going demi by not casting spells, instead slowly increasing their attention by performing appropriate activity with appropriate focus items.
For example, performing surgeries with a focus item of Flesh. A fact that's mostly meaningless for the non-initiated, means a lot to initiates.
Sufficiently powerful focus items can go beyond that. It's not unheard for some particularly powerful to develop an ability to allow one to actually cast spells rather than make them slightly stronger. This requires more than simple 'accidental' exposure, and is typically created by a powerful mage, cultist or a demihuman.
It's achieved through quasi-ritualistic means, for example by having an appropriate item (preferably out of aligned paramaterial be worn or continuously used in ways strengthening the focus. It requires a high degree of profficiency in both magic and more mundane means of gaining focus, and quite a lot of time.