One time I was in Mexico with my wife while our daughter was still a baby and the lady at the front desk of the hotel where we were staying offered us a crib we could borrow. It was a kind gesture, but I was a little concerned because the crib seemed wobbly. I realized there were some screws loose but though I had a multitool on me, the holes were stripped.
So later, I was talking with a local and he's like "I can fix that." He comes over and pulls a pack of toothpicks out of his pocket. He sticks one into each hole and breaks it off so that it's not sticking out anymore. Then he drives the screw back in. I shook the crib after that and it was rock solid!
Now I always keep some toothpicks handy. Fast-forward to just this year. My daughter is now an adult living in a condo, and was complaining the screw popped out of a kitchen cabinet door when her roommate yanked on it too hard. "I can fix that."
Another adjacent life hack is when assembling flat pack furniture, use a quality wood glue on all the joints and connectors, but especially those little wood dowels. It won't make it indestructible, but it'll hold up far better over time.
I’m so glad you posted this - my integrated fridge door has dropped slightly after being taken off and put back on when installed. Can’t really screw back into mdf/chipboard/whatever and I’ve been stressing about getting it fixed for months because whilst it’ll get worse over time, it technically works and no doubt the fitter would say I need to take the whole thing out and replace the side panel.
Sometimes fridge doors sag because the bushings on the hinges break or deteriorate. I've fixed them before by adding washers in place of the bushings, or cutting a new bushing out of a hard plastic cutting board.
You can do something similar with damaged metal threads, instead of toothpicks using copper wire strands. Project Farm has a video on the technique comparing it to other fixes: https://youtube.com/watch?v=jknMrFOGMOQ
Well the toothpick shifts to one side as you put the screw in.
The problem with a stripped hole is that the hole is now as wide as the screw, so the screw has nothing to grip anymore. Conventional wisdom in this case is that you should get a wider screw and try again, but that's not always something you have on hand, especially when travelling.
But the toothpick hack takes it the other way. It's effectively narrowing the hole again by taking up space in it, and now your same screw can work again.