Don't you love these students. Fortunately, these are the minority, but take the majority of your time. I have found it helpful to document all my interactions with them in an unofficial journal format. This includes formal meetings with documented forms, but also in passing or during a break when they come talk to you. This is incredibly helpful when they come back to you 2 weeks later and state something you said, but with their own 'twist' on it. You can refer to your notes, times, dates, etc and that usually sends a strong message about the assignment deadline or grade. How do you deal with these students effectively?