From the first day of class, students need to know what behavior is expected and what the consequences will be if they choose to violate classroom rules. An discipline plan clearly spells out the consequences for breaking rules so students know what will happen if they misbehave. For example, your plan might state that the first infraction will result in a warning, the second in a phone call home and the third, an office referral. Talk to your students about how classroom rules often mirror those found in the workplace, which they are about to enter.
The best way to solve discipline problems in the classroom is to prevent most of them from occurring in the first place, according to the Vermont Department of Education's publication "Guidelines for Discipline Plan Development." When you develop classroom procedures and teach them to your students, you provide the guidelines they need to behave appropriately in almost every circumstance. Adults working in an office building need to know what to do when the fire alarm goes off, and the same is true for high school students. Review campus policies and meet with other teachers so you can align the procedures you teach with those in other classrooms.
When a discipline problem does arise, treat your high school students the same way you'd wish to be treated if a police officer pulled you over for inadvertently violating the speed limit. Be respectful, and speak calmly to address the misbehavior. If a student argues, refuse to engage in the conflict. Simply state the rule that was broken and the consequence, and let your student know that you know he usually makes good choices and hope he will continue to do so. Don't take a violation of classroom rules personally, and it will be easier to address problems objectively and dispassionately.
You can establish a comprehensive set of procedures for every situation and classroom rules that are reasonable and fair, but if you don't enforce them, they're not worth the paper they're printed on. In his book "Tools for Teaching," Dr. Fredric Jones notes that there are no degrees of consistency: You are either consistent or inconsistent. To keep your classroom running smoothly, enforce rules consistently, regardless of how you feel, the weather or the distraction of the junior/senior prom being held that evening.