Widespread testing.
Contact tracing for folks who have COVID-19.
Quarantining people who have it.
Not sharing indoor air for extended periods of time with people who may have it.
Wearing a mask or face covering when within 6 feet of other people.
Putting time and money into building an adequate PPE supply and treatment facilities.
That's a reasonable start. But there's some issues and extras:
1. Widespread testing - which must be rapid and free.
2. Contact tracing - can become quickly overloaded unless the base case count is very low. Recent minor infection group in Adelaide, Australia, where about 25 confirmed cases resulted in some 4,000 people being instructed to isolate. As the number of positive cases increases contact tracing exponentially increases and can very rapidly overrun tracing and testing capacity.
3. Quarantining - it's not only for people who have it. Applies to those who have been exposed
Which then gets on to extras....
Since Australian borders are effectively closed to non-citizens the biggest transmission vector we've had is failures in compulsory quarantining (in Govt managed facilities) from returned Australians. A major problem here has been the gig economy - casual workers who end up working in multiple facilities/industries to make ends meet. Workers get infected accidentally at a quarantine facility and then take it to the next place they work. Which may well be a pizza place or an aged care facility. It's pretty clear from posts here that no-one wants to miss out on ski season and skiing is a discretionary activity (for most). Now consider that a worker who needs those multiple casual jobs to pay for food/rent/clothes for self and family and they are going to go to work even if they have some symptoms. Casual employees don't get sick leave.
I also think most carry on regardless folk are kind of missing the point. Yes, it is possible to reduce our own risk profile by masking and minimising interaction so we can continue favorite activities. But we don't live in a vacuum. All activity results in interaction for some-one. Drive to the snow and it uses fuel. Which means some-one has to be at the fuel station. It has to get deliveries due to that extra demand. Cars break down, roads need policing. And on it goes for all the support activities required to get people from A to B and keep them fed and sheltered away from home. Of course everyone has an activity that they think is special, mostly harmless and should therefore be treated as an exception. And it probably is low risk for them. But all those exceptions add up to increase the total number of interactions.
The outbreak in Melbourne (population 5.9m) , Australia, that kyboshed their ski season got up to 700+ cases per day. Pretty small outbreak by some standards. They tried specific lockdowns, right down to individual buildings (cluster of high rise apartments). They tried suburban lockdowns. It went some way to stopping growth but did nothing to get case count heading down. And the apparent randomness created a great deal of hostility in the affected communities. Cases only went into decline when they got serious and locked down all non-essential activities. Melbourne has now enjoyed >20 days of zero community transmissions and have few remaining restrictions. (Belgium OTOH had a similar case count to Melbourne's back in August - but whilst Melbourne trended to zero, last I looked Belgium were >15,000 cases per day and in a world of hurt.)
Folks, I sincerely hope you get some skiing this season. I was able to enjoy a few trips to the snow in my state. But that was only because they closed the state border in a timely manner to prevent the Melbourne outbreak spilling over. And the rest of Australia had virtually zero cases of community transmission.