Simple discipline technique - being positive! I used to give time-out after time-out and this is more effective for my 6-year-old. I count 1-2-3 before moving his name down to give him a chance to correct. And an end-of-day reward is great incentive to stay in the 'Happy zone'.
With a bit of tweaking this can be used for older children too..Remember ADHD kids are about 30% behind their peers in brain development.. So they may need reminders/incentives for stuff you think they ought to know..