How do you pick the right idea to invest in, when you have many good ones?
The usual answer is a scoring grid. Plot everything on impact against effort, or calculate an ICE score, and put the rest in a backlog. That tells you how to sort a list. It does not tell you how to choose.
Lesson 66 of Inspiration for Innovation starts somewhere else, with how the time is spent: "One of the most frequent mistakes is spending too much of time generating ideas, leaving hardly any time in the ideation workshop to converge, select, and improve them. You should spend at least two-thirds of your timing on picking and improving the right ideas and only one-third on getting a lot of ideas." Not the other way around, which is how almost every ideation session is actually run.
The second correction is about whose judgement you are using. "I learnt in my innovation practice that there are huge differences in how people from within the company perceive new ideas and how their potential customers perceive those same ideas. That's why I advise you to incorporate idea reflection workshops with potential customers in your process."
Together those two change the shape of the work. Choosing stops being a meeting at the end and becomes the larger half of the process, and the people who will actually buy the thing get a vote before the money is committed.
Two neighbouring lessons carry the rest of it: lesson 60 on the seven criteria a strong idea meets, and lesson 62 on the twenty-eight idea killers, the reflex rejections that quietly decide which ideas never get considered at all.