- postponing air travel
- avoiding most gatherings
- wearing latex gloves in public to remind myself to not touch my face
- handwashing upon returning home
- wiping phone/laptop/handles/knobs w/ alcohol 1-3x daily
but consider that if you make fun of people who are trying to not get sick or infect others for Internet Points, you might just be sort of an awful person
If someone in your life becomes terribly ill from this, it'll be because someone else inadvertently infected them. Don't let that be you.
The US is being particularly irresponsible in its handling of an early-stage apparent pandemic, and San Francisco is an especially vulnerable urban hub. My personal precautions are callibrated to my sense of the risk here.