Trustworthiness is among the most important characteristics a teacher can display. When teachers are trustworthy, there is no doubt in the minds of the students, parents, or colleagues that the teacher makes classroom decisions based on what is best for her students.
Trustworthy teachers have obvious motivators - and these motivators are student driven.
If you are giving assignments, scheduling tests or quizzes, or starting projects for any reason other than your need to either help students learn then you are taking a risk. Students do not care that you think you need more grades in the grade book. Parents are becoming more and more aware of the "busy work" nature of many homework assignments.
Be obvious in your desire to help students learn by making sure that your decisions about your class are clearly driven by student success.