The following ideas about refereeing may seem obvious to you.
Most scientists know instinctively how to judge a scientific paper.
If the first version of the report below is too boring, try the second, negative, version, which follows it. How To Be A Good Referee Respond promptly to the Editor's message asking whether you are willing to referee a paper. Remember that it will take just as long to referee the paper several weeks from now as it will today. You will be an anonymous referee unless you specify otherwise. If there is further correspondence between you and the authors, be sure to copy all the messages to the Editor.