The reviewer guidelines are often overlooked by authors, but they contain a wealth of information that will help with the preparation of a manuscript. Knowing what the reviewers are asked to assess when reviewing a paper will help you to structure your paper and address these points when you are preparing your paper. Some of the questions that reviewers are asked to answer include:

How important are the results?
Depending on the journal, the results need to be important to either a general audience or a specialist audience.

What is the significance of the work?
Similar to importance, the significance of the work is also a subjective opinion that could differ between referees. It is important to highlight the significance in your manuscript.

Are there any flaws or weaknesses?
These comments would be particularly useful when revising your manuscript. It could be useful to have your manuscript read by a colleague or an independent researcher. The Science Editorium offers a manuscript health check service, which is not an expert review but it does highlight any flaws or weaknesses that are obvious.

Has similar work already been published? Is it cited? Do the current results confirm or contradict earlier findings?
It is important to cite similar work, and more importantly, to highlight the differences between your work and work that has already been published.

Are the hypothesis and the conclusion supported by the data?
A critical point that is the basic requirement for acceptance by any peer-reviewed journal. A negative response to this question can usually be avoided by not making

Are there major issues in the presentation, such as language, structure, or data presentation?
This usually results in rejection or request for major revisions. You should get the manuscript read by a native English speaker, or use our manuscript health check service to highlight major issues in the manuscript.

The questions below highlight other areas other issues that would need to be addressed before publication:

Is the length of the manuscript appropriate for the content?

Are there places where the meaning is unclear or ambiguous?

Are the correct references cited? What else should be cited?

Is citation adequate, or excessive, limited, or biased?

Are there factual, numerical, or unit errors?

Are the figures, tables, and schemes appropriate, of sufficient quality, and properly labelled?