The author used Apple Configurator to turn their iPhone into a 'dumb phone' by restricting access to certain apps and websites, resulting in a significant reduction in screen time. This was done by setting up a configuration profile that disables the App Store and limits access to specific websites. The author found this setup to be effective in reducing distractions and increasing productivity. The process requires a factory reset and some initial setup, but the author provides a step-by-step guide on how to do it.