This is my editing process:
First draft: write or dictate a the basic scene/chapter/story. I often use a voice to text software while doing domestic chores or dictate into my mobile while out walking and transpose it to text later).
Scene Brief Edit: I add in as much description and sensory experience as I can, filling in any plot/story gaps. Any additions, alterations or amendments to the plot/story are immediately corrected and/or added to previous chapters (otherwise I will forget about them) - same with any prefiguring required.
Grammar Edit: here I concentrate on sentence, paragraph, and dialogue construction - making sure everything communicates what I want to say in the way I want to say it. All grammar and vocabulary are sorted out at this stage, together with the majority of syntax issues.
Sound Edit: this where everyone tells you to read your writing out loud. I find that difficult to do, so I get the computer to read it to me using text-to-speech software. This is were I pick up sound issues, syntax, and readability issues.
Hope this helps,
Nick