The disgusting "mellow/yellow" procedure practiced during water-shortages, or implemented to lower your consumption of pay-per-gallon city-water.
Rather than practicing the "soft drink" water-saver rule to save on my utility-bills, I collect rainwater in buckets outside, and then use that some of the time to flush my toilet.
People who work in project management and client interaction and know exactly what to say, who to blame, when to do to save the ass of their weak little developers and company. Usually paid medium-sized bucks
A do-it-yourselfer who never discards the little screwdriver-tips that come in boxes of torx deck-screws, even though there's always a fresh bitincluded in every box of screws.
My buddies jokingly call me a compulsive torx-bit saver because I don't throw out still-usable screwdriver-tips from boxes of screws, but I figger that, hey --- I already paid for the tips when I bought the screws, so why not save them in case I need one to use with other screws in the future?
In video games: Manually saving your game over and over again (usually before important decisions/boss battles, etc.) to make sure that if you screw up later on, you can always just return to your most recent saved game.
Used in games that allow players to save whenever they want, thus making the game substantially easier because there's no real penalty for messing up, and it lets the player know what to expect ahead.
If I wasn't save scumming so much, I would've had to restart this mission a shitton of times.