I use vinca, heuchera, fuschia, cane begonia, stachys in all my shady/dappled morning sun areas. Mondo grasses don’t seem to mind these conditions either. Geranium are also not too particular in my experience.

Sword ferns, Japanese maples.

Ferns..all. For height you cant beat the Australian tree fern. Tough plant too for a fern. Clivia is a nice evergreen. Azaleas. Some in the bay area get by on average watering. I used to use southern "sun" azaleas for fast growth..and did fine in part shade. They like a dry air warm summer like Cupertino.

If its deep shade..groundcovers like baby tears give lots of green lushness..then dot in a plant here or there instead of shrubs everywhere.

The classic temperate CA shade plant is the camellia japonica. I'm biased since I really like camellias, but they bloom in the winter when most everything is still dormant, are available in a huge range of sizes, bloom types and colors, and they will live for decades and only get better with age. Since they are relatively slow growing, although some cultivars are quite vigorous, camellias are one of the few garden plants where buying a larger size pays off. They do have some demands, most importantly they can't be buried too deep when planting, that is a common mistake and the plants won't thrive if not planted correctly. But given some care, once established they can become one of the backbones of a garden.