I basically start collecting everything that has power and can provide power. Basically I just check on my laptops, power banks, phones, the bag of random batteries, estimate how long I can keep going, and try to reasonably save power regardless: Shutdown instead of sleep for laptops, mobile data off on phone if not needed, prefer dedicated flashlight over to phones, fetch other options like candles.
Kills enough time that the power gets restored during that time. Then I think of how unprepared I was, how I am going to improve it, and then never do it. There's a bag of old 18650s from power banks and laptop batteries under my bed for like 2 years. I don't know what state they are in now. I know I measured their capacities, disposed of dead ones, put good ones into the bag, planned to use it for a giant power bank, but did absolutely nothing with it in the end.
I should probably dispose of them at this point. They all had like 60% of capacity anyway and years of use.
And then I also think about the bag of batteries from dad's disposable vapes. They're rechargeable, but it's possible they were overdischarged and shouldn't be used anymore. On some the wires running along those batteries were partly melted too.
I should dispose of that too. So much damn waste.
In the end after each power outage I turn to the web, obsessively looking through power banks, get amazed by those with built-in mains inverter, but in the end don't get anything as it isn't necessary.