We know that local authorities issued guidelines about how to use the cane, but I think these were mostly just very general “dos” and “don’ts”. (They usually said “only on the hand or bottom”, “never on the bare flesh”, “not more than 6 strokes”, and sometimes “not in front of other kids”, “only by a teacher of the same gender”, and “no group punishments”.) They didn’t give instructions about how hard to hit, what part of the bottom to aim at, or all the things that modern recreational spankers are told to pay attention to. Perhaps, in the Olden Days, most of the people who became teachers had been Prefects when they were at school and had learned how to give out canings “on the job” as it were.
by the 60 and 70s prefects would certainly not have been allowed to use the cane. And I expect that the sorts of people who became teachers had mostly been well-behaved, conforming children who were never in trouble.