Inform your child that he should model his relationship with his teachers after the way he treats other important people in his life, such his grandparents or family friends. Such skills as listening before speaking and properly addressing the teacher are paramount. One of the best ways to convey this information is to talk to your child before the start of the school year, then regularly consult him to ascertain whether he is treating his teacher properly.
At the beginning of each school year, introduce yourself to the teacher. Most schools provide forums, such as parent-teacher conferences and greeting days, to meet your child's teachers. Tell your child's teacher to immediately notify you if your child commits any errant or egregious behavior. Also, your child's knowledge of this agreement between you and her teacher can help deter her from behaving disrespectfully.
You must show your child that you treat others with respect. If your child witnesses you berating and hurting people, he may repeat what he sees. On the other hand, your child will be more likely to treat others with respect if he sees you treat people in a positive and respectful way. This includes everybody from your wife to the grocery store cashier. Respect for teachers begins with respect for people at home and in public.
You shouldn't brag about your child or her accomplishments to the teacher. If you do, it may place extraordinary burden on the teacher, making him think that you don't feel he's good enough to teach your child. Moreover, if your child knows you boasted of his successes, it may cause him to feel he is better than the teacher or that the teacher can't provide him with a valuable learning experience.