The best way to become a developmental editor is to first gain editorial experience in a different role. Start by working as a copyeditor, where you will learn the fundamentals of editing skills, such as grammar, punctuation, syntax, and consistency. After mastering the technical aspects of editing, begin reading more extensively on the craft of writing. Read literary works and editorials to understand the nuances of tone and structure.
Another valuable experience is taking an internship or apprenticeship with a local publishing house or editor. This will provide you with hands-on knowledge of the entire writing process, from concept to editing to publication. In addition, the internship experience will give you an opportunity to test and practice your editing skills in a professional setting.
With experience in your field, it is time to determine the type of developmental editor you would like to become. Research publishing companies and independent editors in your area to understand the kind of editing you would like to do.
Finally, reach out to some of the publishers and editors you have researched and inquire about an internship or apprenticeship. You can also apply to freelance editing jobs to get started with the trade. Evidence of your editing experience, such as writing samples, will be necessary to establish yourself as an editor.
With the right skillset, a good support system, and a lot of hard work, you can become an effective and successful developmental editor.