Redirecting misbehavior
Our impulse when a child misbehaves is to react, which you may not realize, just reinforces the misbehavior. Instead, redirect the behavior to something better, then praise them when they do the new behavior. Start early, this is difficult to work when they are teenagers.
*sees a kid drawing on the wall with crayons* “Can you help me draw a picture of some puppies on this paper?” Draw with the child then praise them for using the paper. Their subconscious desire for your attention was what made them draw on the wall. Now when they feel the impulse for your attention, they will draw on paper, reinforce this by drawing with them.
*sees the teenager spending a lot of time on their phone/video games/etc* “I’ve signed us up for martial arts classes, we’re going tonight at 7:30 PM, get ready to go please.” During class you smile at them as you are having a great time, they will have a great time too. After class you tell them how much fun you had and how much you loved watching them train. The next night instead of being on their phone, they are asking if tonight is martial arts night.
Over time this can really make dramatic changes in the child’s self esteem and their positive behavior.
TLDR: Try not to punish misbehavior, redirect the child to do something good, then reinforce that good behavior with praise and attention.