Revision never stops, it is an ongoing process. Even already published pieces could always use a little more work. Dont' like to revise? Think your writing is perfect the first time around? Well, sorry to sound a bit harsh, but GET OVER YOURSELF. Even the greatest writers in history spent years in the revision process before calling their works complete. There is always something you could be doing differently.
Looking for a good book on the process of revision? The Craft Of Revision, by Donald M. Murray, is a great one.