Jessica Eastman Stewart, in an episode of the Joyfully Managed Life podcast, introduces the concept of 'deciding once' as a tool to reduce everyday decision fatigue and stress. This proactive approach involves concrete decisions forehand to eliminate repetitive thought processes, increasing efficiency and freeing mental energy. Stewart illustrates this concept with various examples - a friend's weekend routine, her household's dishwasher usage policy, and her vacation plan in the case of rain. Other scenarios include her predetermined weekend Starbucks visits with her children. The podcast encourages listeners to implement this strategy in their lives for easier and joyful management, further expanding on the concept in Stewart's Instagram highlights, titled "Deciding Once at Joyfully Managed Family".