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'.
Instead of banishing your children to the dungeon every time they have a hissy fit, why not use this clever 'Time Out Stool'. http://kids.ideas2live4.com/2015/04/02/make-a-sandglass-time-out-stool-for-the-kids/ You can make one using a recycled plastic bottle. What do you think?