What are your macguyver gear fixes in the feild?

Sorry to anyone who doesnt know who macguyver is. Basically here meaning to fix things in a pinch with random stuff you have lying around.

I'll give an example; one time I was out in the middle of a hunt documenting the story of Indigenous hunters. Lens suddenly descides to have electronic failure and doesnt want to talk to the body, wouldnt let me take photos or adjust anything. My macguyver fix? A small peice of paper between the lens and body elements when I mount the lens. Now it operates like a fixed aperture, manual focus lens. Wasn't perfect, but it saved the shoot.