Some medical facilities dispose of metal tweezers instead of running them through an autoclave. Wasteful, but whenever a family member or I are treated, I make a point of scrounging any that are used if possible. Occasionally, when I've asked nicely, I've been given the odd pair. Invaluable for camera repair tasks, particularly the needle tipped type. I'd be lost without mine.
Rubber inner tube can be very useful for loosening tight fasteners or resting a part on without damaging it while you are working on it, particularly if you have to apply force Eg to loosen something.
Rubber sink plugs from hardware stores come in various sizes. Some of the natural rubber ones can make decent tools for loosening the filter rings or optical groups of small to medium sized lenses. Remove any metal handles first, obviously.
Hardware stores and tool shops sell coloured mats made of rubber for lining tool boxes to protect tools. These are perfect for the top of your work space. Cameras and other parts you are working on will not be scratched or scuffed on a mat. They last for a year or two, are inexpensive. When one side is eventually looking tatty or discoloured, flip it over and re-use.
Auto paint polish may be used to restore a shine to painted camera bodies. Some can contain silicones, best kept away from optics. But only trace amounts are needed—I usually dab a cotton tip on the nozzle, and am still working my way through the small sample bottle of Autoglym I scored years ago. Whilst nowhere near as aggressive as a cutting compound they will remove surface deposits fairly effectively with the appropriate amount of finger pressure and leave enough of a protective coating that this will help protect surfaces from skin acids and sweat for a while. They're very handy for freshening up a camera in need of a proper clean, and I've returned numerous tired-looking examples to near new condition. Also useful for certain types of metal surfaces such as aluminium, if you want to polish them up without resorting to potentially more aggressive metal polishes—works a treat on Carl Zeiss Jena lenses, for example.
