Create a constructive classroom environment through communication to deal with behavior issues:¹

• Take a preemptive approach by defining expectations in the syllabus and again discussing them at the first class meeting.
• Decrease anonymity by forming personal relationships with students.
• Seek feedback from students.
• Encourage active learning.  

Handling disruptions:²

• Use language in a de-escalating fashion by strongly and assertively requesting the behavior stop rather than ordering the behavior to stop.
• Assume a positive intent when addressing student behavior.
• Speaking with the student in private and encouraging a change in behavior might mitigate future disruptions.
• Asking the student to leave is an option – use it if necessary.  

1. http://www.scf.edu/pages/PDF/Library/DealingTroublesomeBehaviors.pdf
2. https://students.wisc.edu/pdf/Handling%20Classroom%20Disruptions.pdf