Now that you've decided and used which ever method of revision you'll be using what happens now? Done, done, you think. That's not necessarily so. What you need to do at this point before you send the mss out is to do a read through, Often in reading the story you';; find the little things that take away from the story being as perfect as you are capable at the moment. The words the spell check missed because they're really a word but not the right one like way for was or other words like this. You might also find punctuation marks, particularly ? marks you've missed. There are other things to read for. My method is to print out the story in single space and to use a ruler to go line by line. This keeps me from becoming so involved in the story that I forget why I'm reading. There are other points to consider.
Point of View == Is this consistent and the changes smooth, Are you forcing the reader to follow the bouncing ball>
Show not tell -- Are there passages when you go back to read that you're told when showing will make the story sing?
Sequencing - Does the action in a scene flow in a direction that the reader can follow or do you have several sentences that are out of place. Once write a scene when the hero discovered something before it happened.
Does a scene run past the effective point sort of like those goodbyes that go on and on when no one wants to close the door? This calls for some cutting.
Has the tone been consistent or have you thrown in a section that sounds like someone else has written it> I've found this often happens when research material has been introduced and the writer turns to the teacher voice.
These are things you may not find either when revising as you go or doing a number of drafts and could be a chance an editor won't buy or a reader will hate your book.