One way to teach children self-restraint is to teach them limits. You can do that by setting various age-appropriate rules. Decide on what consequences there will be for breaking certain rules, and be consistent in implementing those consequences. Some parents also have a lot of success in teaching kids self-restraint by involving their children in martial arts.
I am thinking so much our children's lives are filled with so much stress at school, at home, in the neighborhood. I know how the anxieties of my parents affected me. I know their care for my invalid sister and two other siblings left me more anxious in different ways. Also since I was the oldest, I think I felt my parent's anxieties also.
I feel this created higher average stress in me that hurt my thinking, learning, motivation to learn and in addition, created pent up energy from that stress that continually sought relief through some form of activity. I feel many children today who are seen as ADD or ADHD are really suffering from higher average internalized stress from various sources that then come out in more active impulsive behavior as a natural outlet for that higher stress. I feel behavior modification will not work as it does not solve the problem of higher average stress that will continually be seeking relief. I think all of us greatly affect those around us in different ways. We can all learn to approach our lives more delicately to help both ourselves and others.