Codrin, in your survey, no mention "others"
In that cathegory, I find the position important.
I have always made my children bend over - lately even touching toes - in order for the bottom to be presented as well as possible for the spanking, making it possible to give the most effective impact on the bottom.
You also mention parts of the body to punish.
I am sure most of use punish the bottom most, maybe followed by the thighs.
I don´t know any parents, who punish their children´s footsoles (thank God!) I have heard of a few who punishe the palms of the hands and some who punish the back.
Actually, I use the latter for my daughters, it is necessary to punish them while they have their period.