I have spanked several women, three with a cane, one with a ruler. I remember all of them visually. I'm amazed how relaxed their bottoms were and believe me I was definitely looking closely.
One woman asked for it and always wanted more, her bottom was always quite relaxed. She was older than me and I was very inexperienced. I didn't know what I was doing and regret that I did not indulge her more often. Her ass was amazing, light brown and so tight and round. I did enjoy when she let me "examine" her spanked bottom in the days following, a good excuse to get her to drop her pants and pull down her panties.
The second woman usually got spankings with my hand but toward the end of our relationship I began using a cane, which obviously hurt more. She didn't cry but she would whisper "But I'm a good girl" as I caned her. She never clenched her ample bottom and I know the spankings got her aroused, because I would spread her and see how wet her vagina would get during. Her spankings always ended in anal intercourse, which we both preferred to vaginal.
The woman I spanked with a wooden ruler was a brief affair, a co-worker. She was very loud and alpha at work and very quiet and obedient once her clothes came off. The one time I used the ruler on her bare bottom, she lay totally still and counted all the strokes and I ordered her to do. I told her to "relax" and her round white cheeks never clenched but they were very pink when it was over.
The last women was a long time girlfriend who I caned many times with a wooden dowel and a thin hard plastic tube. She hated and loved the pain. So sometimes she would clench her cheeks, not sure she could help it sometimes, depending on what was going through her head. Either way it hurt and she shouted out or into her pillow. Those strokes almost always left pink welts on her very pale white bottom for several days.