Set a high standard for the product
Build something useful, then keep raising the standard.
An idea, a plan, and a presentation do not solve the customer’s problem. A product must do that work. A founder needs an active concern for the details that make the product useful.
This does not mean treating every detail as equally important. It means learning which details change the customer’s experience. You develop that judgment through use, observation, and repeated changes. You do not develop it by keeping the product away from customers until a large launch.
Put the product in front of people who have the problem. Watch how they use it. Find where they stop, misunderstand, complain, or return. Change one part when that helps you understand the result.
A major improvement can come from a small change. You may not know which change will matter before you try it. Repeated tests create more opportunities to find it. Product judgment therefore combines a demanding standard with a willingness to learn from reality.