The Georgia results, not unlike Alabama 2017, show that there is synergy between behind the scenes electoral organizing — building the machinery to maximize turnout for your side — and confident, aggressive campaigning.
One of the things that stands out about Warnock and Ossoff is that they did not campaign as if they were afraid of backlash. And I think that refusal to take a defensive crouch was an important part of neutralizing Republican attacks.
If there are lessons for Democrats in other red states, I think these are the places to start. Constant, year-round organizing of the kind spearheaded by Abrams and begun years ago, candidates that fit the coalition, clear policies and, again, aggressive and confident messaging.