Craft assignments to be specific and clear, and review them in class to be sure they are understood.
Assign shorter writing. A series of short assignments can be as effective as one long paper. And an assignment you have designed carefully can be more effective in teaching writing than a open-ended but long term paper.
Sequence assignments so that ungraded assignments lead to a major graded assignment or a portfolio of best work.
Build grading into assignments as you design them. Include grading criteria or a rubric with the assignment prompt (See Assignments and Grading and Commenting). Predetermine how points or grades will be assigned so you can grade more quickly and fairly.
Include on your assignment prompt any grading notation or symbols you commonly use and explain them.
Include on your assignment prompt any policies that affect your grading, and review them with the class. For example, you may warn students that you will not physically mark every error in grammar, spelling, or punctuation, even though you may take off for them.
In designing a rubric, weight the comments so that not everything must be commented upon; in other words, comment upon those aspects of the assignment that you deem most crucial to success. It is especially useful not to mark every error or infelicity.
Train graders to use a rubric; have them "norm" in one or two sessions by asking them to use the rubric to grade a few identical papers. They should discuss their differences and adjust the rubric or their grading until they reach an acceptable level of agreement (which you determine).
Provide as many opportunities as possible for students to consult with you, with peers, or with the University Writing Center as they write (see Help for Students).
Students contesting grades can eat up your time, so develop a fair policy and be consistent in applying it. Many writing instructors require a 24-hour cooling off period: students must wait for 24 hours before contacting the instructor with questions about grades. Others request that all inquiries about grades be made in writing.