When the kids are jumping up and down for chocolate and video games, it’s easy to get into the habit of saying "NO!" or "Don't" all day long! While it's important to use firm words sometimes to alert our kids to danger, try to steer clear of creating a negative environment, and give positive parenting techniques a go.
It's as simple as turning that "NO" into a "YES" by rephrasing your response. Instead of saying "No, you can't play a game until your room is cleaned"try saying "YES, of course we can play a game, just as soon as your room is cleaned"
This kind of answer gives your kids a choice and makes them feel empowered.