You could apply a little oil to the anus and surrounding area before spanking it. Start by having your lover assume a comfortable position that exposes the anal area
I found coconut oil works best for this . I don't apply ithe warmed oil with my hand or fingers . I use my penis to apply the oil . That is far more intimate . A shallow container like a saucer works well for this. Coconut oil absorbs into the skin and is supposed to be healthy btw.
For your lover , this is TLC. Very intimate TLC.
You are preparing her bottom cavity, her most intimate cavity, for a love spanking.
More often an impromptu spanking of the anus by an erect or semi erect penis is in order. However this way is a special treat, at least , that's been my experience.
Oiling the area that will receive loving discipline is a special treat. I like to make it last by rewetting my penis with the oil several times and massaging the anus a bit, thereby sensitizing it .
After admiring thé oiled shiny anal area, I start slowly (spanking) allowing the pain to become pleasure. Slowly increasing the cadence as you would in any erotic spanking. At the end of this erotic discipline I finish with a few really hard wallops of my penis on her bottom cavity .
Massaging the ass cheeks from time to time adds to the sensations you are lavishing upon your lover. A few light hand slaps upon her bottom cheeks adds to it as well.
This is like sharing a special and intimate moment together .