My strategy for writing reviews is to:
- write a short summary listing out what the primary contribution is of the work (see first paragraph of my sample reviews below)
- write a short summary of my overall thought as to whether the paper should be accepted or rejected (see second paragraph of my sample reviews below)
- write a paragraph for each of the main parts of a paper and offer my opinion on how well the authors did
Of course, there is no right or wrong strategy for writing a review.