From Joanna Hare in the blog PhD2Published:
Read the journal’s aims and scope first!
An editor’s receptiveness to a query letter has a lot to do with personal preference, with most stating that they do not mind receiving letters. However, it is critical that you demonstrate that you have an understanding of what the journal is about. You can make this clear in your letter (for example, ‘I have read your journal’s aims and scope and my work fits these guidelines for reasons A, B and C’).
If you are not already very familiar with the journal you are submitting to, I would recommend going further than reading the aims and scope to reading several of the articles published in the journal. This will give you an idea of the writing style and topics covered, and how your article would fit in an overall volume. Referring to specific articles in your email to the editor is also evidence that you are familiar with the journal and committed to publishing with them.
Know the journal and editor
Kevin O'Gorman, professor of management and business history at Heriot-Watt University, provides a list of tips to get published in a journal.
One of those tips involves understanding the scope of the journal. He writes in the Times Literary Supplement:
Journals are not just waiting for your paper, nor do they just publish whatever comes their way, regardless of quality.
For example, the highly ranked and cited business management journals can have up to a 98 per cent rejection rate, so you need to be on top of your game.
The journal is normally seen as a conversation; you need to embed your work within it. Make sure that you have read any editorials on the nature and scope of the journal. Often editors when taking over a journal wish to take it in a particular direction; make sure your paper fits within that plan. If in doubt, a short, courteous email to the editor never hurts.
Always follow the correct submissions procedures
From Tangali Sudarshan, editor, Surface Engineering, who provided this tip for The Guardian:
Often authors don’t spend the 10 minutes it takes to read the instructions to authors which wastes enormous quantities of time for both the author and the editor and stretches the process when it does not need to.