Someone recently asked what it takes to become an editor. Here’s my response:
The first rule of good editing is the same as the first rule for good writing: read. Read a lot. Read carefully. Then reread. What did you notice the second time that you didn’t the first? Train yourself to look for these things.
Know the different types and styles of edits. Understanding the differences between them and the expectations and nuances of each is critical.
Get familiar with current styles—meaning Chicago, APA, etc. Language is continually evolving, as are the “rules” for writing. When Elements of Style was first published, words like today and tomorrow were hyphenated! There are probably many rules you learned in school that are now as outdated as “to-morrow.” (Have you noticed the trend toward single quotation marks rather than double for dialogue?)
Another thing to get familiar with: various software. You will likely receive work in different formats, and you’ll need to be able to work with all of them.
Remember that you must be a good listener and a clear communicator to be an effective editor. An editor’s job is not merely to mark up paper but to help writers improve. You must understand their needs and be able to explain reasons for your suggestions clearly.
Consider a certification course.
Practice! Do critiques for writers, take an internship, or offer to help a professional editor. Find some way to get in the trenches and develop your skills.
When you’ve gained experience and feel confident, take a few Chicago quizzes to see if you’re ready. (Okay, you don’t have to do this, but it is a good guide to readiness. I didn’t begin charging for edits until I routinely scored 90-100% on these.)
Prepare for business. There’s more involved than reading. Research fees, contracts, etc. and have them ready to go. Create a website. Print business cards.
Then put yourself out there! Build a network with publishing associations and writers’ groups as well as editors’ associations. Consider doing a few very low cost or even pro-bono edits to build a portfolio. (Publishers and writers love a bargain as much as anyone.)