That sugar trick @margaretramirez mentioned is one of those old-timer hacks. You see it everywhere once you look. People in every trade have a weird little fix like that. A plumber I know uses dish soap in his flux. Just a tiny bit of something ordinary to solve a specific problem.
Try sprinkling a little sugar on a stripped screw head before you drive it back out. The grit gives your bit just enough extra bite to grab what's left of the stripped metal. It's saved me a bunch of times on old cabinet hardware. Those little tricks stick around because they actually work when you're in a pinch.