We used to make use of the telephone, and would think up plausible gags, ironically it used to work quite well, and sure wish we were smart enough to have recorded them, good clean fun, some of the reactions were priceless, a few would get angry, most would laugh/fall for it, resulting in actual appointments and what have you. Business's were the most fun as they provide services and gave you more content to work with, vs a residence which was really no fun to be honest, whomever was on the extension listening had to play it cool or lose your cover. Now whomever was the perpetrator, also had to keep it cool, fight off laughing.
The other thing I can recall is using cigarette loads and placing those in my mothers cigarettes, I hated the darned things way back then, and you would have to carefully push the load back far enough into the tobacco so it did not go off when she lit up. Just like the cartoons, the splayed paper resulting from the pop, was picture perfect, and these little white pieces of thermite or what the heck they were certainly loud or powerful, kind of ticked her off, I just hated cigarette smoke in the house, car what have you, never worked, she's still smoking like a feign today.