But just checking that the world of my story is logical (even magical worlds have rules) and that I am consistent within that, by checking the characters are coming across the way I meant them to do so - now that I'm not frightened of and I find it reassuring when I find, yes, the story does make sense. I can then "relax" a little bit and focus on editing for grammar, spelling, can I improve the way I've expressed things (and the answer to that one is always "yes"!!).
I do at least three edits on a story - I ensure the structure is right first, then move on to copy editing and improving the way I've written what I have before having a gap and then coming back to the story with fresh eyes. If at that point I'm happy with it, I send the story off. The gap is crucial. It's the only way I've found to really come back to a piece of work and read it as a reader would.