You've found a partner willing to exchange manuscripts or WIPs (works-in-progress) for critiques. You know what not to do in giving and receiving critiques. Still, your hands tremble as they hover over the keyboard. What do you write? What do you look for?
I prefer receiving thorough critiques, and unless told differently that's what I give. Some writers prefer tackling one thing at a time (i.e. story structure or plot or characters alone), but it's hard for the reader to keep re-reading the same story. Things tend to get overlooked when you've read it six times already. But if that's what they want, that's fine. Just be sure to know what your critique partner is looking for beforehand. Some people suggest not to critique grammar if you're critiquing a first draft. I try really hard, but I was an English teacher, it's not something I can turn off easily. So I say that's your call.
I'm not going to talk about the etiquette of critique writing. I did that last week. If you missed it, have no fear, go HERE. To read this series from the beginning, go HERE.
This is about the nuts and bolts of writing a thorough critique when asked for.