I'm attending the Rocky Mountain Fiction Writer's Conference in Denver tomorrow and the first session is a critique group with an editor. Each of us received a copy of the other members' first ten pages a couple of weeks ago. Feedback is critical for me to understand where the major issues are in my work, so I assume other writers feel it is critical as well. Here is the process I use to critique, hopefully you'll find it helpful.
1- Read it through twice.
This is merely to get a feel for the story and a feel for the writing style.
2- Simple proofread.
During the second read, focus on grammar, punctuation, sentence structure, consistent verb tense and basic mechanics are distracting. This is a relatively easy thing to help fix.
3- Plot flow.
In a macro sense, analyze all the scenes for organization, clarity and flow. If something doesn't make sense or requires a reread to understand it, then make a note.
The dialogue needs to sound natural. I love the term "conversation hijacking." The more writers observe everyday conversation and read other authors, the more likely the dialogue isn't cheesy.
5- Word choice.
This is almost like line editing. Every single word of each sentence needs to be effective.
6- Point of View.
Maintaining a consistent point of view (POV) allows the reader to dive into the book without distraction.