Nothing much. If the infection breaks out near you, avoid crowds, wash your hands frequently, and don't touch your face (especially nose) with said hands. SARS and it's ilk kill the old and sick, not the young, so avoid your grandparents or elderly parents.

If there's little or no infection near you, I wouldn't do anything yet.

Vector reduction.

That's the principle mechanism of public health to epidemiological outbreaks: reduce the likelyhood and rate of transmission between people.

This is why the appropriate response is to curtail transport, especially long-distance modes which occur faster than onset of symptoms (e.g., air flights from known epidemic zones). It's why locking down cities within epidemic zones, restricting mobility between cities where outbreaks have occurred, wearing barrier protection to prevent both contracting and transmitting particles, disinfecting infected surfaces, and limiting social and business contact, are all primary responses.

Get a flu shot, if you haven't already. Not because it'll keep you from getting 2019-nCoV, but because you don't want to be confusing having the flu with having nCoV, and you don't want to have to be out getting treated for flu whilst nCoV's circulating. And having all others treating you like Typhoid Mary to boot.

Wash your hands.

Carry (and use) alcohol-based hand sanitiser. (Antibiotic is useless against virus.)

Wash the doorknobs, light switches, taps, knobs/pulls, and bannisters in your home, regularly. Keep visitors and guests to a minimum. Don't touch your hands to your face, eyes, nose, or ears.

Look for indications of breakout in your area on news or online. Realise that if there's a breakout, the disease has likely already been circulating for several weeks, e.g., the risk is high. Currently, outside of China, there are very few places at risk -- Singapore, Hong Kong, Japan, Korea, Japan, Thailand, and South Korea are the major additional locations.

Transmission seems to require several hours of fairly close contact.

Stocking up on cleaning supplies generally makes more sense than masks, which are of limited use or efficacy.

Some somewhat nonobvious practices (salt-infused masks, apparently, others may exist) seem to reduce transmission or viral capability profoundly.

For now, the containment trends are strongly positive, outbreaks outside China are quite limited, and it looks as if measures are effective. It'll be another few weeks before this is certain, things could still go quite badly, but signs are encouraging.

Most notably, the new cases and deaths trends are dropping well below their initial exponential trajectory:

https://en.m.wikipedia.org/wiki/2019–20_Wuhan_coronavirus_ou...

https://en.m.wikipedia.org/wiki/2019–20_Wuhan_coronavirus_ou...

Comments I made yesterday on Diaspora regarding this, and pointer to a now 10-day-old post based on the then exponential growth, in which I'd suggested we should see containment working on new cases by early February, and deaths by mid-February (we're actually trending well ahead of that):

https://joindiaspora.com/posts/17158824

Disclaimers: lay views, not an expert.

Unproven and likely wrong but I saw a speculation that MMR vaccine and rubella boosters may provide partial protection explaining why so few children and young women are amongst the casualties. (from https://foreignpolicy.com/2020/01/26/2019-ncov-china-epidemi...)