What to do about students who ask for help too often?
Here is one strategy:


Specify the level of changes the student needs to make before they can come back again.  
Request that the student shows you what changes have been made by comparing the old and new versions of the assignment.  
If student has failed to reach the level suggested or fails to show you the differences, simply tell them to go away until they have made the requested changes. Simply state that your previous comments still apply.


Adding a time delay between when they ask and when you give feedback or when you give feedback and when they can come again might also help.