If you encounter defiant behavior from a student, try to develop a positive relationship with the child. For example, make a point of recognizing him whenever you see him around the school or when he comes into class. Initiate some informal discourse. Give him some attention.
If you have one or more defiant students in your class, try a strategy which entails an early monitoring of activities. Defiant behavior often evolves from a particular situation and this is commonly during group work. The defiant student may gradually reject the ideas of others and ultimately show this defiance with an outburst or blunt refusal to work. If you see this developing, you can intercede as you see fit, for example by changing the composition of the groups.
It is often the case that defiant behavior stems from feelings of rejection. These feelings can originate from home or from perceived indifference by classmates. Assist the student in overcoming his problems by one-to-one discussion. Giving the student individual attention may in itself be a first and important step. Another is being attentive, tactile and caring during the meeting.
Defiance has several different levels, and you should be prepared for all of them. Perhaps the most extreme is when the defiance leads to severe aggression or even violence. Agree on a strategy with your principal for dealing with this. If this happens, it may just be the endpoint that can be used as a reference for helping the defiant student in the future. He has made his ultimate point, so he may now accept reason.