You are busy with your thesis or doctorate. You have identified what you wish to write a about and have narrowed your focus. You understand about your advisory team and have a good or not so good relationship.
When does one engage an editor? Does on engage a professional academic editor?
Anyone who has written anything for public consumption knows that one edit is not enough. Editing is like an onion or a ladder. One needs to keep editing until it reads well. The more one strives for excellence, the more one needs to peel another layer/edit to get it ever-refined. Or another image. One edits and gets to an acceptable level. If one wants to improve the quality, one needs to climb the ladder and have repeated edits.
Students have one professional edit, make changes, and think the work should still be perfect. It’s not and even one change or non-acceptance of even a small part of an edit can mess up a perfectly good edit. So if you are looking for anything close to perfection, pay for repeated professional edits. As I always try to remind students: writing is a dynamic process and not a static process. Layer by layer; step by step.
I have yet to write anything that I have not repeatedly read and repeatedly changed. Depending on time and importance, I get someone else to look. With your own work you always miss something. So pass it on to others to also read for you.
And next is what kinds of editing are available to you. But if in a rush to see what a good editing service offers, browse around the Language Online website.