For those of you who aren't Trek fans, let me 'splain my title. No, wait. Is too much. Let me sum up: The Borg, in Star Trek fandom, is one of the Federation's ultimate enemies. The Borg is a Collective where no one is an individual. All independent thought is suppressed. The goal of every drone is the betterment of the Collective. A little like a bee hive or ant colony, only focused on universal domination and the destruction of all other sentient and independent beings. (Insert political joke of your persuasion here if you choose.)
But being part of a collective doesn't have to be evil. It can be a good thing. No, no! I haven't gone to the dark side. Even though in the mornings when I run with my headlamp, my beeping Garmin watch, my headphones, my reflective gear, etc. etc. I may look like a cyborg, I'm still mostly human. Mostly. ;-)
Back to the point.
When you work in a critique group or if you ask others to read your work and give you feedback, you are part of a collective. You're putting your minds together and trying to reach a common goal: a better piece of work. It may be your piece or theirs. It may be a piece you're working on together. In any case, as a collective, you have to work together to re-work the writing into a better piece.
There's one thing, though, that we humans often forget when trying to work as a collective: leave your ego at the door. This is for all parties involved. If you're asking for help, read the help with an open mind and realize the comments aren't meant as a personal attack but as a way to improve your work. Conversely, if you're trying to help, make sure you're making suggestions that will help improve the work, not just point out its flaws. And also praise the parts that are good, too.
See how this works?
Years of violin master classes and college critique groups have toughened my skin quite a bit. I can take a tongue lashing (or a red pen lashing, as it were) pretty well. However, I'm not everyone. Some people come out of their first collaboration/critiquing session and swear never to do one again. Worse, they swear never to write again!
So next time you're asked to look at someone's piece and give your opinion, consider this: collaboration is a jeweler's kit, not a jack hammer. Give them gems that highlight the jewelry they crafted, not break the concrete of the foundation they've tried to build.