Here are some tips for you to give effective feedback on one's writing:
1. Use composition guidelines.
--Thesis Statement/Topic sentence
--mechanic skill: Grammar, Spelling & Punctuation
2. Point out the positive and negative aspects of the work.
--Do not forget to give reasons
--Give examples if possible
e.g. Your tone is perfect or your points are clear and easy to skim because ....
3. Focus on small parts which help your readers find the information faster.
e.g. Can you think of a title that tells what's in it for the reader?
4. Ask questions because questions can help the writer and you think.
e.g. Do you have specific data that might convince readers?
5. State your arguments or debate.
--State what you think no matter whether you disagree or agree with your peers.
e.g. Although your viewpoints sound workable, we still cannot make 100 percent sure. For example, ....
Assignment: Discuss and Give peer-feedback.
Group 1 --> Group 2
Group 2--> Group 3
Group 3--> Group 4
Group 4--> Group 1