Try shooting large format, and you will find many opportunities and ingenious ways to spoil the shot, whether it's kicking the tripod after carefully adjusting all the camera movements, pulling the darkslide without closing the shutter, clicking the shutter without removing the darkslide, forgetting to stop down the lens, forgetting to set the shutter speed, forgetting to focus with a press camera, etc.--there's a long list in one of the articles at lfphoto.info.
Sometimes, though, two mistakes can cancel each other out. Once this summer I was making a photograph of my wife and myself with the self timer, which I don't often do, and had only two sheets of color film left. First shot was okay. Second shot--everything's okay, cock the shutter, trip, oops--forgot to set the self timer. Fortunately, I also forgot to pull the darkslide, so I had a second chance on that one, and that was the keeper.