Whether you are doing the editing yourself or you are thinking of hiring someone, you should know that an editor determines if the copy will be stand out. Some of the qualities that make a good editor are:
One thing that sets editors apart is the passion they have for the job. A good editor must be passionate enough about the editing job, and the topic that they are editing on. They must be able to appreciate the ups and downs of editing, including the long hours that they may sometimes have to put in to ensure the writing they are editing has a proper deadline.
This is closely related to passion. A good editor should be patient enough to work with people. There is a lot of content including ebooks that need editors, and the only way you can take up such roles is when you are patient. There will be moments when you have to work with a big volume of work and you can get frustrated if you are not patient.
Knowledge of Subject Matter
If you do not know about the content that you are editing, you will get frustrated. You will also end up doing a shoddy job because you will not know what to leave out and what to add in the copy that you are editing. Do intense research and consult deeply before you start editing.
Good Command of Language
Good editing needs you to have a good command in the language of the writing that you will be working on. You should understand the grammar, spelling, and structure so that you can have an easy time editing the piece that you are working on. You should consider using other software such as spell check if you want to make things easier, but you should never forget that even such software gets it wrong sometimes.