There's a lot of different ways to look at the editing process but this is personally what works for me:
Draft 1. Just get the story down. You can go back and look at things for consistency's sake but honestly don't worry about anything but getting your ideas down.
Draft 2. Make it make sense. This could be as simple as rewriting a line where you said a character is blond but is actually a brunette, or as complicated as completely deleting and/or rewriting a certain scene. Usually it's a combo of both.
Draft 3. All about character. Are your character's actions consistent? Would they really say that line? Are you sure?
Draft 4. All about style. Would that character really say that word? Does that paragraph have a good enough transition? ect.
Draft 5. Just another go around of the two above. Character consistency and style are very important, my friends, and you may need another Passover.
Draft 6. Spelling, flow, ect. You're reaching the end now. Polish it up.
Draft 7. Just reread It 3-5 times. Edit anything and everything you can.