The phrase "to do some editing" means making changes or improvements to something, usually a written document or a piece of creative work, in order to correct mistakes, improve clarity, or enhance its overall quality. Full definition
As a professional editor myself, with 15 published books, my publishers did the editing for years. (thewritelife.com)
Unfortunately, I can't advise because I didn't do edits on the previous books from this publisher. (madgeniusclub.com)
Create a series of short stories, do a piece of non-fiction, write a script or pages of poetry, or even spend the month doing edits of your novel's first draft. (feedspot.com)