I often lost small parts like derailleur springs. Then I bought a cheap magnet tray for my bench. Now, I place every screw and spring on it during disassembly. It saves me a lot of time looking for dropped pieces. My repair work goes faster since I began this habit.
Got the same kind on my toolbox after losing like five screws in a row, lol. Upgraded to a bigger one that holds wrenches too, no more crawling around on the floor.