1. Check the journal’s Instructions for Authors,
2. Check to see if the journal’s Instructions for Authors have any requirements for cover letters, e.g. disclosures, statements, potential reviewers.
3. Then, write a letter that explains why the editor would want to publish your manuscript.
a. Please find enclosed our manuscript, “[manuscript title]” by [first author's name] et al., which we would like to submit for publication as a [publication type] in [name of the journal].
b. To our knowledge, this is the first report showing…
c. We believe our findings would appeal to the readership of [journal name].
d. Please address all correspondence to:
e. We look forward to hearing from you at your earliest convenience.
4. All cover letters should include these sentences:
a. We confirm that this manuscript has not been published elsewhere and is not under consideration by another journal.
b. All authors have approved the manuscript and agree with its submission to [insert the name of the target journal].