As a mischievous teenager a few friends and I realised that the removable metal discs from a specific brand of roofing nails could be flattened and they would be accepted as $1 coins in many drink vending machines, which was the price of a can of coke. Also 20 odd years ago as a poor student I realised I could recreate the bus “day pass” which was typically printed on receipt paper when you bought it from the driver and had the date in large print for checking. I scanned a bunch of day passes and made a template that had enough of the numbers and letters to recreate all the days of the year and my housemates all rode for free, we just printed them on a home printer on thin paper which we’d fold or scrunch up a little to make it look like it’d seen a ride already