I feel that ideas are very fragile, so you have to be tender when they are in development.—Jonathan Ive.
Sir Jonathan Paul "Jony" Ive is an English designer and the Senior Vice President of Industrial Design at Apple Inc. He also provides leadership and direction for Human Interface software teams across the company. Wikipedia
Building products isn't factory work, yet we often act as if it was. Ideas are very fragile. And whether you're in development or in a strategy meeting, let people express their ideas without instant condemnation. For that matter, let them finish their thought! Don't interrupt, extend!
It's a technique from improvisational comedy: Always accept the premise. When someone says, "How are you feeling?" provide an answer that moves the bit forward. "I'm fine" doesn't; it just grinds the bit to a halt. "I just had a fight with my boss and I'm still mad" gives the comedy team something to run with. The same is true for brainstorming, whether with a colleague or a client.
Ideas are fragile. Be tender.