Ironically, peer editing someone’s work actually benefits ourselves as much or more than the other writer. That’s because we’ll inevitably notice aspects of our paper that we need to tweak and improve upon. Seeing others’ work helps with our own.
It’s also useful to remind ourselves not to be too nasty with comments to others (or ourselves). That’s where we can confuse criticism with judgment. Students are usually harsher with evaluating or grading peer work than any professor! Be positive and specific. Avoid being like those elementary kids who, when called upon for Show and Tell, end up stating “Here’s my essay. I like it a lot. It’s really good.” Really and other junk works can be avoided both in our peer editing and essay writing.
Again, the key is to be positive. Ask questions and be specific.
Jot the things in your own paper which this peer editing reminds you to fix. They are there if you are open to noting them. In fact, this is all about noting: Mark, remember is another synonym for notice.