Have him Bring you the instruments for punishment. Just when you are about to give him a major spanking, whipping, or other punishment, make him go get the tools for you to do it.
If you have told him in advance that you will be having a “conversation” with him later at night, make sure you also give him the instructions to have certain tools and/or toys perfectly washed and laid out ready for your conversation (Make a list of the instruments you want, plus a glass of wine, or anything else). Then give him an exact time, to the minute or when, where, and how you want him to report to you for the “conversation”. That will give him several hours to contemplate in fear about what you have in mind for him.