It's been a little while since I've actually received a disciplinary style spanking. Usually if I'm about to be spanked, I don't really have many thoughts at all. Although, a good scolding can have me feeling like "uh-oh, I'm in trouble." But this is more in the scolding style and demeanour of the spanker than the act of spanking itself.
On the other side of things, when I'm giving a spanking, there is a lot more thought given to the practicalities of it. What am I going to say? What implements am I going to use? Making sure I'm aiming right with heavier implements and so on.