I started using the cane on my son’s bottom when he was 10 years old. Up until about seven, I had merely given him a few smacks on his trouser seat when he misbehaved.
However, he gradually got inured to this punishment, getting up from my lap afterwards and telling me that it didn’t hurt. My response was to start taking his pants down and smacking his bare buttocks. This had a more salutary effect, but it wasn’t so much the increased sting as the embarrassment of Mum seeing his private parts that did the trick. Unfortunately, over time he also become somewhat accustomed even to this.