in my opinion a real punishment should hurt both of us. That may not seem to make sense but it true for me. When she see she has made me mad or disappointed me that often is enough but if it is very serious then I will make it a very hard punishment one that will hurt her where she lives. This takes knowing her very well and using that knowledge against her. Rare that she will ever do the transgression again, and this very act will hurt me deeply that I feel I have to do this.
That said it will not be anything that physically hurts her, I do expect her to endure some pain from time to time just to please me. This is not punishment but a show of true submission.