I found out the hard way.
Then one day I met a woman, she looked after children...and was brilliant.
I found out she had certain 'tones', that she would use.....but never did she use the one for discipline of any child...without it really being needed.
So the children would know, ''oh! that's the serious voice...we had better behave.''
It was not used Unless....a tantrum was being thrown.
Not once was her voice ever raised, but each child did what she said 'once' she had their attention, with this very special tone.
The golden rule is, never ever scream at a child....In time, they do learn how to turn off.
I had a Doctor once tell me, Totally Ignore the child...once they see you will not react, they will stop...and in time may never do it again.
He was a specialist in children.
I also would Google for info...see what they are saying these days.
P.S.
I will tell you one thing I have seen...that I do not agree with.
Distracting a child is Not a good idea.
Tell you why, the child is still upset...still frustrated! ....it only leads a child to being more upset later.Whatever upset the child, may not be earth shattering...but they did experience it.Children need to learn how to interact with others, without tantrums.(Parents or whoever)..so buy showing the child a Tantrum is not going to yield good results...they will stop in the end.