There are five key principles for achieving sustainable productivity: first, stop demonizing procrastination and instead focus on understanding why you're delaying a task; second, divide your tasks into "raise the bar" (high-priority) and "good enough" (low-priority) categories to optimize energy and time allocation; third, fill leisure time with a combination of active and passive rest activities to recharge creatively; fourth, take on less work than you think you can handle by determining your capacity through time tracking and adjusting accordingly; and fifth, embrace flexibility in your schedule to accommodate individual tendencies and needs. By applying these principles, individuals can achieve a balance between productivity and self-care, leading to a more fulfilling life.