I realized recently that I rarely have complaints / grade challenges from students. On occasion I do make a mistake-- and occasionally I'll have a student ask me to review or reconsider a grade, but it's been years since a grade complaint made it to my Dean's office.
I think I know a few reasons why...
I'm very clear about their grades, expectations and what's due. This includes using a grading matrix that is very simple and justifies the grade. I also write the next assignment on the board every class period. I know the little dears won't keep up with the syllabus -- and they often don't arrive on time, so that way they have no excuses. You can't say you didn't know what was expected if it's written on the board at the front of the room EVERY FRIGGING CLASS.
I tell them what I expect and I grade accordingly. Students complain when they're surprised -- I spend a lot of time (perhaps too much) in class making sure my expectations are clear.
I provide a way for them to know where they stand in the class before the last assignment. This lets me clear up any clerical errors I might make (and I do make them), and get stuff in before it's too late. It also prevents the surprise D. They know at least a couple of weeks before I enter it that they're heading to D-land...
I have a minimal number of standards/expectations, but I hold to them. I think I could raise my standards/expectations for writing a bit, at least for Bioethics which is a smaller course.
I have a limited number of 'mulligan' opportunities. This gives students a chance for a do-over -- without becoming a huge burden on me. I want them to demonstrate their abilities, but they also have to -- at some point -- be able to deliver. The combination is important because it allows a student to learn what they aren't understanding about an assignment/topic and then makes them actually do it. The limits are an important part of the 'do it' phase, as some students won't learn until they have to.
I'm also pretty transparent in terms of grading and my own experience / duties as an instructor. So I'll tell them when I expect to get something done -- but, also if it doesn't look likely for a while... if I have a huge stack of papers and another class needs theirs back first, generally classes understand this. Their anxiety comes when a professor promises a specific date and then doesn't deliver. When they realize the time-management game that is being a CC prof, it helps them see and appreciate both the effort that goes into giving a thoughtful grade and helps them understand the time line necessary for giving that grade.
Being transparent about my own time management challenges helps to explain my reason for delay on grading late papers. I tell them that I have a specific time period set aside for grading their papers. When papers miss that time period, the students can't expect immediate feedback... they need to wait for the time period I have reserved for 'misc, grading', which is usually at the end of the semester.
So -- what do you do to make your student relationships easier to deal with???