Little exercise here and helping a fellow Magician enthusiast out. He was asked to give descriptions for his Foci, and the character is a female and a bit of a bitch.(Not sure if personality will help but why not)

Power Focus (2) Sustain Focus/Detection (3), Sustaining Focus/Manipulation (3), Sustaining Focus/Health (3), and Sustaining Focus/Health (4). Descriptions are for these 4 Foci, they also have Two Fetishes, One combat one Health. I can only think of mondane simple things like rings, necklaces and earings which for a hermetic mage work I guess.

Also they are German.

Keep in mind that nearly anything can be enchanted as a focus, and that hermetics often (but not always) favor modern items such as credsticks, pens, etc. Some suggestions would be - compact with mirror, pair of sunglasses, antique pocket watch, charm bracelet, ornament braided into hair, or key ring.

Here's a list of more traditional objects: Wands, staffs, books, precious (cut) gems, hats, robes, embroidered fabrics, belt buckles, boots, prosthetic limbs (glass eyes is my personal fave), amulets, brooches, monocles, gloves, canes, scarves.

If she's a controlling bitch, probably go with things that aren't easily taken away--piercings, understated jewelry, and the like.

More of an arrogant bitchiness, should have more flamboyant items--oversized sunglasses, choker, jeweled hairpin, etc.

Setting personality aside, when describing foci, I tend to go with the old geasa rule that an object should have three descriptive factors. It helps build more character into the item and when changing (especially if the character enchants their own gear), the new details can support a change. Having "gold-rimmed, aviator sunglasses, with etching around the edges of the lenses" gives a better sense of the individual than has "a pair of shades."

And for a different sort of character, the description could just as easily be "a pair of beat up old black shades with a scratched lens". That actually strikes me as a pretty good way to do it.

Cool. I use it for any of the signature items for a character, not just foci.

Yep, I do this too...