Consistency is the key to successful discipline, but that doesn’t mean you shouldn’t also be flexible. If your child’s bedtime routine includes lights out at 8:30 p.m. sharp and you never, ever veer from it—even on special, once-in-a-blue-moon occasions—your routine may be too rigid. It’s important to build in a little flexibility. For example, has your child been studying hard for a test? Why not reward him with 15 or 20 extra minutes of reading time in bed one night?