One way to avoid this harm, while still sharing harsh feedback, is to follow a simple rule: if you’re going to say something sharply negative, say something genuinely positive first, and perhaps something genuinely positive after as well. Some people call this the “hamburger” rule, other people call it a “shit sandwich.” Whatever you want to call it, finding something positive to say about something you don’t like forces you to consider the possibility that there is something actually good about the idea, even though all you might notice is what isn’t working. It’s your responsibility to search for both and share both good and bad aspects of an idea.
I agree with this portion of text. This is something that I see people do in non-design contexts, and something I do in my every day life. I use this tactic a lot at my workplace when training new hires. First, telling them something their doing a good job at, then telling them something they still need work on. I can see how this would work in a design environment too.