The principle: prioritisation through subtraction.

Most time-management advice focuses on fitting more in. The opposite is the actual skill: deciding what not to do. A ruthlessly short priorities list forces focus. A ruthlessly curated calendar protects time for what matters.

Every yes is a no to something else. Saying no generously to good opportunities is how you preserve capacity for great ones. The best productivity systems are just tools; the decision to subtract is the work.