I'm not a dom or a sub. But, from my experience, I adore to be spanked with a paddle. Wooden one, ofc. I preffer ping pong and a large, round paddle.
My gf prefers leather. She just threw out one of her leather whips. Personally, I'm not into the pain aspect although it's hot to see her with one.
Well, usually, it's not my decision about the amount or about how hard. But, I adore the pride my spanker feel, when he sees my very very red bottom, after a session. And ofc, instant change of behavior. For better. LOL And the paddle is mostly the famous jokari "atitude adjuster".
I like both. Cat of nine tails leather , riding crop ,leather. And a 5 gallon paint stir stick are my favorites.