Look for things to praise, especially in students who are discipline problems. Other students who also want praise will follow. Accept these students as worthwhile, in spite of their misbehavior. Disapprove of the act certainly, but not the individual. Do not try to do the impossible.
Some students have emotional problems only a better-trained person can solve.
Control your temper. Flying off the handle merely shows students that they have gotten to you. Do not be afraid to apologize if you have treated a pupil unjustly. Delinquent behavior may be normal behavior in a child's cultural background. It is important that you understand that background.