Disciplining your kids is hard.
It requires nuance. You can’t yell all the time, because it loses its effectiveness after a while. You can’t spank ever because you were spanked by your parents when it was acceptable and are now you are totally insane and probably in jail. You need to develop tricks. Time-outs, good cop/bad cop, the Parent Voice, etc.
Most of the time, getting your kids to behave boils down to two strategies: threats and bribes.