General considations
Some journals require a pre-submission enquiry from authors requesting to publish papers in their journal. The conditions of this enquiry depend on the type of paper you as an author wish to publish. For example, for the international ecology journal Trends in Ecology and Evolution, authors wishing to submit a Review or Opinion paper must submit a 500–600 word summary of the paper, including co-author information and up to 20 references primarily from the last 2–4 years (http://www.cell.com/trends/ecology-evolution/presubmission). The Editorial Board of the journal will then deliberate on whether your paper is deemed novel enough, is appropriate for the journal readership, and if it falls within the scope of forthcoming journal volumes. From submission of the enquiry letter to decision typically takes 2–3 weeks.
Authors can find information on pre-submission enquiries on individual journal websites and are encouraged to discover as a first step whether a pre-submission enquiry is required for the intended journal.
Practical example for Life Sciences
Within the life sciences, journals that require pre-submission enquires are a minority. The best practice when submitting your paper is to first define its message, shortlist a list of potential journals, then check the website for each journal to see whether they indeed require a pre-submission letter. As this letter usually requires a succinct summary of the relevance and novelty of your work in the context of the broader field, you would consider writing this letter once you have written your paper and are confident with its direction and intended message. In some circumstances, it is possible to write to a journal with an idea for a paper without having written the paper itself. This is usually applicable when you intend to write a short comment piece in response to a recently published and topical paper.
Practical example for Social Sciences
It is a growing trend to ‘preregister’ a study plan with a journal by providing a summary of the study aim, hypotheses, planned method, and expected findings prior to commencing data collection (for example, PLOS ONE and Cortex). By pre-registering publications can opt to commit to publish the results, irrespective of the novelty of findings, based on a strong methodology and theoretical basis as part of the Open Science Framework (https://osf.io/). Yet, this it almost impossible to find a journal that requires this for publication, and it is still fairly uncommon for journals to require a pre-submission enquiry.