Often we find ourselves giving negative commands to our kids, "don’t do this", "stop doing that". The things we tell our kids not to do outweigh the things we tell them to do.
The alternative: experts say, save the ‘NO’ for truly dangerous situations like if they stick their fingers in an electrical socket. Instead tell them what you want them to do. Also explain WHY they shouldn’t do what you’re asking them not to instead of just demanding. For instance, if your kid grabs his sister by her hair, instead of yelling NO, say "look, you are hurting your sister and it’s making her sad". Also use positive parenting by praising them if they listen to you.