Mine is a combo. For my essays, poetry and short stories, I work alone and don't use an editor or anything, and I think it's served me pretty well. Probably because those projects are so much more streamlined focusing on one set of events, I don't have any trouble keeping myself on track, and I am 100% sure I know what i'm going for every step of the process. Also, though I'm awful with punctuation, I can usually fix stuff for myself with the help of Grammarly on projects under 10 pages. But when it comes to my novel I am working with an editor/proofreader, because
- it's super helpful to have a second set of eyes for those times where I rewrote a sentence, but forgot to ENTIRELY rewrite it, or remove the original sentence.
- my grammar is atrocious
- He's also kind of a developmental editor, helping me make sure the chapters are moving smoothly and actually moving the plot forward, don't seem awkward, characters behaviors and such are staying consistent. He's really good at understanding the story and what makes the most sense for it and the characters, so while he never tries to domineer the project, he's there to point out the rare moments when a character's behavior seems out of place with their nature.
So, do you just trust your instincts when you write? Do you run your works past and editor, or even beta readers to get a second (or third or fourth) opinion, or do you just go with what you prefer?